Enhancing Sustainable Cosmetics Brand Purchase: A Comprehensive Approach Based on the SOR Model and the Triple Bottom Line

: Proﬁtable and dynamic, the cosmetics industry strives to conform to the environmental ideals and practices of the 21st century. For years, NGOs, the media, and consumers have accused cosmetics brands of pollution, environmental disasters, and safety concerns. These allegations can spread faster in the online environment and cause genuine brand crises. Many cosmetic company managers continue to assess the necessity of accelerating their business toward sustainability initiatives and being more consumer centric. Therefore, this paper aims to examine the impact of economic, social, and environmental sustainability on brand attachment and brand attractiveness, which may result in a positive WOM, enhance purchase intention, and ﬁnally lead to the intention to join online brand communities. To implement the research scope, the authors developed a conceptual model based on the triple bottom line (TBL) and the Stimulus-Organism-Response (SOR) approach. To assess the conceptual model, the authors have conducted quantitative research, through an online questionnaire, with data being collected from consumers via an online survey platform. The snowball sample comprised 1632 valid responses from consumers of sustainable cosmetics brands. Further on, the conceptual model was assessed employing structural equations modelling via SmartPLS. The results conﬁrm the impact of the three pillars of TBL (i.e., economic, social, and environmental sustainability) (stimuli) on brand attachment and brand attractiveness (organism), which ﬁnally generates positive WOM, triggers purchase intention, and enhances consumers’ intention to join an online brand community (response). From a theoretical perspective, our research contributes to extending knowledge based on the SOR approach and TBL applied to sustainable cosmetics brands. Considering the signiﬁcant effects of economic, social, and environmental sustainability on consumer perception and intention, the study also pinpoints some major management implications for the cosmetic industry.


Introduction
The World Commission on Environment and Development introduced the term "sustainable development" in 1987, in the Brundtland Report presented to the UN General Assembly [1][2][3].Since then, the concept has been largely used in many areas, keeping its power of pointing out the essential issues for humankind.The "triple bottom line" (TBL) describes an entire sustainability agenda that is focused on a balanced view of economy, environment, and social justice [4][5][6].The economic, social, and environmental pillars are seen as strongly connected to achieving sustainable development goals [7] and resilience in time of crisis [8].TBL represents "the emerging 21st century business paradigm" [4,[9][10][11], p. 20, situated at the forefront of branding [12].A major brand could not be defined today in the absence of "big impact sustainability commitments" [13][14][15].Sustainability-based corporate identity has become the nucleus of contemporary firms [16] and is consistently communicated to stakeholders [17].Reports show that people are also becoming increasingly interested in this matter [18][19][20].
The cosmetics industry has changing general trends that try to align with sustainable principles and practices.Sustainable cosmetics represented, for a long time, an oxymoron.Firstly, cosmetic products were traditionally associated with vanity, as nonessential items [21].Despite this perspective, cosmetics cover a very large category of products [22,23], with multifarious roles, from ensuring basic hygiene to raising self-esteem and social prestige.Secondly, animal-testing methods, use of chemical ingredients, unethical natural ingredient sourcing, pollution, environmental disasters, packaging composition, and safety issues created many controversies and led to the reproach of NGOs, media, and consumers.The entire supply chain has a potential impact on sustainability, from sourcing to the post-consumer phase [24][25][26].No wonder, thus, that the cosmetic industry was scrutinized over time.The effects, nevertheless, were positive: many companies took sustainable measures to a great degree and now are listed among the most ethical companies.Corporate transparency at the triple bottom line (TBL) has become a regular activity, alongside the efforts of the brands to communicate with their stakeholders.All the same, the cosmetic consumers of today are informed and connected, seeking brand experiences and making decisions both rationally and emotionally [27].Consumer awareness of sustainability is growing, and people are becoming mindful of the effects of their own purchasing decisions.Thus, they tend to reward sustainable brands and penalize brands that act incorrectly in terms of TBL.They search for ethical and clean products, underlining the importance of "buying cosmetics with conscience" [21], p. 4. Informed decision-making and supporting sustainable companies have become, for many people, a lifestyle that produces happiness, health, and well-being [28][29][30][31].Individuals' preference for safe and healthy products has been augmented, especially during the COVID-19 pandemic [32].Moreover, the pandemic has stimulated "a new consciousness that has spotlighted 'purpose over profit'-a more holistic approach to sustainability that aims to encompass social, environmental, and economic value" [33].
The sustainable cosmetics are an interesting category of brands-the sustainability is hard to obtain and implies, in many cases, a radical change of doing business in this industry.A sustainable cosmetic brand must satisfy difficult criteria to meet the production requirements, the expectations of stakeholders, and the three levels of sustainability standards.Moreover, sustainable cosmetics companies search long-term visions and frameworks that incorporate strong values alongside profit.Additionally, the people are more and more demanding, more aware, and try to buy cosmetics more ethically.In this respect, sustainable cosmetic brands are a stimulating object of research, with theoretical and practical implications.Considering these peculiarities, the literature still lacks empirical studies on sustainable cosmetics [34].Literature privileged the research of the environmental pillar from TBL, neglecting the economic and social dimensions of sustainability [24].Research is mainly based on secondary data [34] or case studies regarding diverse cosmetics companies or product brands [35].The corporate transparency at the three levels of sustainability became a regular activity for many cosmetic brands.Nevertheless, an on-going issue for cosmetic companies is making sure that messages and concrete practices or norms about sustainability reach their public and that customers do not perceive sustainability only as a "fancy" or obscure word [21].The relationship between the sustainable characteristics of brands and how consumers conceive them is another missing link [12].Therefore, this paper aims to fill these gaps by examining the influence of all three pillars of sustainability on cosmetic brand attachment and attractiveness.The novelty of this research consists of adding another important dimension alongside the TBL: social prestige as a key element that has been proven to exert a positive influence on brand attachment and attractiveness [36,37].The paper also examines the purchase intention and word-of-mouth (WOM) towards sustainable cosmetics, as well as consumers' intention to join virtual brand communities, which supports such behaviors.This research extends previous knowledge based on the "Stimulus-Organism-Response (SOR)" framework [38], thus considering as stimuli social prestige, economic sustainability, social sustainability, and environmental sustainability of the cosmetic brands that lead to brand attachment and brand attractiveness (organism), which finally results in WOM, purchase intention, and intention to join online brand communities (response) (see Figure 1).social prestige as a key element that has been proven to exert a positive influence on brand attachment and attractiveness [36,37].The paper also examines the purchase intention and word-of-mouth (WOM) towards sustainable cosmetics, as well as consumers' intention to join virtual brand communities, which supports such behaviors.This research extends previous knowledge based on the "Stimulus-Organism-Response (SOR)" framework [38], thus considering as stimuli social prestige, economic sustainability, social sustainability, and environmental sustainability of the cosmetic brands that lead to brand attachment and brand attractiveness (organism), which finally results in WOM, purchase intention, and intention to join online brand communities (response) (see Figure 1).This paper is structured as follows: in Section 2, we briefly present the Stimulus-Organism-Response (SOR) model, we review the literature concerning the main constructs of the article and, on this basis, we propose the research hypotheses and develop the conceptual model.After that, in Section 3, we present the research methodology, followed by the results in Section 4. Section 5 pinpoints the discussions and the originality of the research, while the last section describes the theoretical contributions and managerial implications, as well as the limitations and future research directions.

Stimulus-Organism-Response (SOR) Approach
The Stimulus-Organism-Response (SOR) model was introduced by Mehrabian and Russell [38], then further developed in the literature [39][40][41].Originally, SOR was derived from environmental psychology.In this framework, diverse stimuli are considered as having an impact on the psychological state of a person that leads to certain behavioral outcomes.Stimuli act as a driving force that arouses the individual, challenging his or her cognitive and emotional condition.In sum, SOR is an approach that depicts the reactions of the organism when external stimuli (S) shape its inner state (O).SOR is a flexible model, widely used in consumer behavior research because it can explain the elements that form the decision-making process [42].SOR has been the framework for recent sustainabilityrelated research [43][44][45][46], and thus also for sustainable cosmetics [47,48].

The Triple Bottom Line (TBL)
The widely accepted definition of sustainability from 1987 [1,13,49] highlights that contemporary society must act responsibly so that future generations could benefit from similar resources to present generations.Agenda 21 [50] emphasized the need to put sustainable development in local, national, and global contexts, while a particular study [51]  This paper is structured as follows: in Section 2, we briefly present the Stimulus-Organism-Response (SOR) model, we review the literature concerning the main constructs of the article and, on this basis, we propose the research hypotheses and develop the conceptual model.After that, in Section 3, we present the research methodology, followed by the results in Section 4. Section 5 pinpoints the discussions and the originality of the research, while the last section describes the theoretical contributions and managerial implications, as well as the limitations and future research directions.

Stimulus-Organism-Response (SOR) Approach
The Stimulus-Organism-Response (SOR) model was introduced by Mehrabian and Russell [38], then further developed in the literature [39][40][41].Originally, SOR was derived from environmental psychology.In this framework, diverse stimuli are considered as having an impact on the psychological state of a person that leads to certain behavioral outcomes.Stimuli act as a driving force that arouses the individual, challenging his or her cognitive and emotional condition.In sum, SOR is an approach that depicts the reactions of the organism when external stimuli (S) shape its inner state (O).SOR is a flexible model, widely used in consumer behavior research because it can explain the elements that form the decision-making process [42].SOR has been the framework for recent sustainability-related research [43][44][45][46], and thus also for sustainable cosmetics [47,48].

The Triple Bottom Line (TBL)
The widely accepted definition of sustainability from 1987 [1,13,49] highlights that contemporary society must act responsibly so that future generations could benefit from similar resources to present generations.Agenda 21 [50] emphasized the need to put sustainable development in local, national, and global contexts, while a particular study [51] introduced the three dimensions of sustainability: environmental, economic, and social.The traditional economic component of a corporation is supplemented by bottom lines for environmental and social performance, summarized as "people, planet, profit" or the three Ps [52].TBL must be considered simultaneously and in a longer-term perspective for significant outcomes.The TBL consists of the interplay between economic well-being, the equality of chances between members of society, and the preservation of the environment.The triple bottom line becomes a standard of sustainability in every domain, changing business models and ways of thinking, and entering the strategies of corporations and governments [53].The number of sustainability dimensions was further increased from three to five [54]: environmental (concern for natural resources), social (equality in pay, opportunities, and work conditions), economic (advancement that secures human needs and well-being), temporal (the enlargement of scope towards future generations' needs) and developmental (emphasis on innovation, lifestyle change, and political regulations) [55][56][57], while other perspectives pointed out the importance of culture as another pillar of sustainable development concentrated on heritage, diversity, and eco-cultural resilience [11,[58][59][60].The classic TBL is not just a metaphor or an idealistic modern goal but remains a valuable theoretical and applicative framework [61].The sentiment analysis of the literature shows its popularity and usefulness in many integrative views [62], and various validations and criticisms were made [16,63,64].

Economic Sustainability
The economic bottom line is more than profit figures, since it encompasses economic and human capital, accountability, and a rate of innovation that assures the company's competitiveness in the longer term [4].The economic pillar is fundamental for sustainable development, even if the early literature did not produce a consensus about the meaning of the economic dimension, providing different understandings of how economic growth could be effectively related to sustainability or how to achieve a balance among the three pillars [65].The critical perspectives on the economic bottom line are also found in the recent literature [16,62].Sustainable economic performance means that companies should be more responsible for the influence they exert on society and the environment [56,66].Contributing to sustainable consumption and production also leads to enhancing economic outcomes for organizations [67], and to shared value [68].The "win-win assumption" implies the common ground between economic and non-financial aspects of sustainability: "saving the world and making a profit is not an either/or proposition.It is a both/and proposition" [69], p. 2. As the economic dimension means that a brand will achieve financial profit to invest in various innovative strategies, that brand could be considered more attractive than non-innovative brands [70,71].A powerful and innovative brand will last longer on the market, so there are more possibilities for maintaining a long relationship with its products.Instead of investing in brand relationships and purchases with cosmetic brands that do not have economic stability, customers could find the meaningful fulfilment of promises in successful brands over the long term.Therefore, we hypothesize that: Hypothesis (H 1 ): Economic Sustainability has a positive influence on Brand Attractiveness.

Social Sustainability
Social sustainability has been neglected or subsumed within an economic prevalence discourse over time [72][73][74].While economic dimensions represent an imperative element for the existence of a brand, the social dimension reflects the actions of the company towards its stakeholders, employees, customers, and society in general.In TBL, social sustainability refers to "wider political, social and ethical issues" [4], p. 84.It contains strategies that can improve the community and its resources [75], social well-being, equality, and social justice [72,76].Social sustainability implies the development of human and social capital, within the framework of human rights, social responsibility, health, education, and safety rules [77].The traits of social sustainability are considered "elusive" and are still under-examined [78,79], even if some perspectives put this dimension at the very core of sustainability [80].Many companies still do not have proactive strategies and actions to address social sustainability [78].The corporate social sustainability culture is still missing in many firms, although it produces many benefits, such as performance and competitiveness [78].Besides profitability, the cosmetic industry must incorporate social fairness strategies.The "social footprint" of cosmetic brands [21] acts as a differentiator tool, motivates employees, and strengthens ties with external stakeholders.Analyses based on the ISO 26,000 or the Global Reporting Initiative as criteria concluded that improvements are necessary, but cosmetics companies achieved positive results and showed concern regarding sustainability [81][82][83].The implementation of social sustainability practices in the cosmetic industry is not easy or fast [34,84] as consumers appreciate not only the quality or the price of cosmetics but also the way their preferred brands behave socially [83,85,86].As the awareness for social sustainability has grown and, for instance, Millennials and/or Zers are key enthusiasts that push the cosmetic industry toward sustainable practices and values, especially for skincare products [22,33], the sustainable cosmetic brands are more valuable and desirable.In this respect, we propose that: Hypothesis (H 2 ): Social Sustainability has a positive influence on Brand Attractiveness.

Environmental Sustainability
The environmental pillar of sustainability refers to natural capital [4,56].The survival of all humanity is closely linked to attaining environmental sustainability.The responsibility for consuming natural resources and the protection of ecosystems, so that future generations have a quality of life at least like ours, stays at the heart of environmental sustainability.Due to its visible urge and importance, the environmental bottom line was integrated into the life of companies and gained visibility in business and research agendas.Environmental concerns are widely mediatized (e.g., climate change, environmental degradation, environmental footprint of businesses), and customers began to be more and more aware of the impact of cosmetics products on the planet.In searching for drivers of sustainable beauty care purchases, 58% of respondents from the UK said that they buy them because "they are better for the environment" [20].Using resources more responsibly and ethically and constructing pro-environmental behaviors [87] became paramount for an industry that pollutes and has "no raw materials and/or packaging materials and practices that can be considered 100% sustainable" [25].With appropriate strategies, the impact of cosmetic products on the environment can be drastically lowered [61,76,86,88,89].As most people care about nature [90] and like brands with a positive approach to environmental sustainability [19,91], the following hypothesis was formulated: Hypothesis (H 3 ): Environmental Sustainability has a positive influence on Brand Attractiveness.

Social Prestige
Prestige represents the way that consumers can preserve and/or increase their social visibility and standing by displaying competence, knowledge, and/or specific skills, thus being able to earn the respect of their peers [92].Thus, it is opposed to dominance, which attempts to gain and maintain social rank through coercion or intimidation.Both of these strategies represent evolution products that are meant to help people find their way within social hierarchies.The relationship between social prestige and brands has been identified as essential since the end of the 19th century, when the literature [93] discussed conspicuous consumers who acted according to their will to showcase wealth and power.This Veblenian intuition was further extended [94] by discussing interpersonal and personal effects.People want to acquire a form of social prestige not only for self-concept purposes but also to access memberships to groups.Consumption of goods for the status they confer is linked to both self-respect and social approval [95][96][97].In the field of botanic cosmetics, no clear-cut effect of social prestige on either behavioral commitment or emotional commitment has been found within the paradigm of susceptibility to global consumer culture [98].Most consumers think that cosmetics constitute an essential element of how they are perceived by other people and a useful tool to control interpersonal communication [99][100][101].The use of cosmetics is associated with social status [102,103], confidence, and competence [101].When wearing cosmetics, women were perceived as healthier, self-assured, and more likely to have prestigious jobs [100,104], in contrast to early research [105].As cosmetics offer status [103,106], not only utilitarian means, it is also expectable that consumers tend to be attracted by and attached to them.In this context, we propose the following hypotheses: Hypothesis (H 4 ): Social Prestige has a positive influence on Brand Attractiveness.
Hypothesis (H 5 ): Social Prestige has a positive influence on Brand Attachment.

Brand Attractiveness
Brand attractiveness refers to any evaluations of the core competencies of a brand's peculiarity and/or associations in a central, distinctive, and meaningful manner [107].This assessment of brands is made most of the time in relation to consumers' self-definitional needs [108].Brand personality dimensions and associations shape brand attractiveness [109].When customers consider that a brand is distinctive, this perception turns the brand into a more attractive one [108].Brand attractiveness constitutes a significant predictor of consumer behavior [107] and of consumers' identification with the image and values of that brand [110].When congruency between personal values and the brand's values exists, this "identity similarity" [111,112] becomes an important driver of attractiveness felt for the brand.In this context, we posit the following hypotheses: Hypothesis (H 6 ): Brand Attractiveness has a positive influence on Brand Attachment.

Hypothesis (H 7 ):
Brand Attractiveness has a positive influence on Purchase Intention.

Brand Attachment
Bowlby's and Ainsworth's work [37,113,114] is considered the starting point in documenting and explaining attachment in parent-infant relationships.By extending research from attachment within interpersonal relationships to attachment developed with object possessions, its application in branding became obvious.When a brand is perceived as the attachment object, attachment implies both a cognitive and an affective linkage of a person with the brand.This could reach the degree to which the latter is perceived as an "extension of the self" [115], p. 4. Consistent with attachment theory [116], the structure of attachment is made not just of emotions, but also of cognitive schemata that consist of thoughts and brand memories [115].Brand attachment involves a bond between the consumer and the brand, with specific effects on consumers (i.e., psychological comfort, connection, satisfaction) and brands (i.e., favorable attitude toward the brand, loyalty) [117].This relationship between people and brands supposes repeated good experiences that lead to durable connections.The personal level of concern for sustainability is a decisive element in the formation of attachment to sustainable brands.In the realm of cosmetics, consumers' emotional attachment is significant [98].The more responsible people act, the more they will be attached to brands with the same values, and this attachment also shapes their well-being [118].There are three main categories of outcomes: willing to recommend, purchase and revisit; resilience to negative information; defending the brand [119,120].Therefore, we propose the following research question: Hypothesis (H 8 ): Brand Attachment has a positive influence on Word-of-Mouth.

Purchase Intention
Sustainability efforts and claims have not gone unnoticed by consumers.Sustainability awareness favorably impacts people's altruism, which, in turn, influences their purchase intention [121].Sustainability is closely linked to positively connoted ideas such as contributing to society, doing good, and care for correct work conditions and the environment [122].For green products, studies have revealed positive correlations between perceived envi-ronmental concerns, green trust, and green purchase intentions [123,124].Consumers are willing to spend significantly more money for "ethically produced goods" [125,126] when the company's perceived intentions are considered fair.They are interested in buying a sustainable product when its benefits are seen as an "unintended side effect"; otherwise, purchase intention decreases because people consider that the respective company invested in environmental enhancements while lowering the quality of products [127].The purchase intention of sustainable new brands is lower than for conventional ones [128].Promotions do not produce the expected result for sustainable new products: sustainability supposes merely a long-time commitment from individuals.Fostering sustainability is a practice that generates positive brand evaluation and purchase intentions, with perceived value as a mediator of the effects of perceived sustainability on purchase intention [129,130].When discrepancies between brand promises, advertising or values, and brand activities are detected, consumers intend to "punish" these brands by lowering their trust and purchase intentions [131].Further, 41% of consumers from around the world are willing to pay more for sustainable, organic cosmetic products [18].Brand image has a significant influence on the intention to buy a cosmetic product, while price promotion was insignificant [47,132].Sustainability, safety, or green-grade traits of cosmetics are difficult to be interpreted alone as triggers for purchase intentions; the perceived social value of cosmetics constantly influences purchase intentions [133,134].Despite the efforts to move sustainability to the mainstream and to develop ethical consumerism, sales of sustainable products remain modest.Many people are concerned about sustainability issues, but this preoccupation has not automatically transferred to buying [135,136].Many other people do not guide their purchases based on the sustainability criteria, so creating facilitators became important [12,[137][138][139].Innovation resistance theory [140] was used to explain the reasons for consumer resistance towards buying eco cosmetics: tradition and image acted as the most significant inhibitors on people's purchase intention, while health and environmental concerns were the principal moderators [141].If after a positive evaluation of a brand a potential client has the intention to purchase it, it is expectable that this potential client will recommend the brand to other people.When a consumer reaches the point of purchase intention, this means that the consumer has built a strong case in favor of that brand.As an effect, the potential buyer will disseminate opinions about the brands deemed valuable [86].The arguments that construct his/her willingness to buy are seldom shared within the network of acquaintances and function as triggers for further recommendations.This is particularly probable in the field of cosmetics, where there is a wide array of choices and WOM represents a valuable shortcut for the complex process of decision-making [91].Furthermore, a potential buyer becomes interested in many details regarding the brand.Thus, he/she wants to connect with other people with the same brand choices, to find out news about the brand, and to comment or post content.At the same time, becoming a part of a brand community fulfils the need for information, engagement, and sociability.An online brand community could offer utilitarian, hedonic, but also monetary values, and a potential customer could find here discounts, vouchers, and free gifts that could consolidate his or her purchase intention.
Therefore, we propose the following hypotheses: Brands have noticed the huge potential brought by the Internet and merely by SNSs (social networking sites) in terms of the number of users, information distribution, and ways to communicate with customers [142].Together with brand pages, a brand could catalyze the construction of online communities [143,144], with members that share the same interest in brand products and activities [145] and develop social capital [146].Branded content is found to be a key element for consumer engagement that could lead to a "customers' sense of virtual community" [147].People choose to join a brand online for many reasons, such as obtaining fresh information, entertainment, socializing, reviews, a sense of community and integration, or searching for status [148,149].Consequently, these benefits generally fall under the categories of hedonism (pleasure, fun), communication, and utility, within the framework of the Theory of Uses and Gratification, Social Identity Theory, and Optimal Distinctiveness Theory [148,150].Informational and interactive posts of the brand, mediated by experiential value, increase the levels of engagement [151][152][153].Cosmetics brands use experiential marketing based on virtual communities to co-create meaningful stories with their customers, while luxury cosmetics promote exclusivity [154].
WOM represents the communication between consumers, potential buyers or fans about a brand, product, service, or corporation.WOM could be spread in many ways and using various channels (face-to-face communication, chats, mobile communication, social networking sites, etc.) [22].Online brand communities are also a channel for brand-related WOM but spreading information and opinions about a cosmetic brand is not identical to engaging in a brand community.WOM represents one of the many activities that a member could do in an online community (reading, playing games, and watching multimedia materials or advertisements are some possibilities).Additionally, the members of brand communities could be both active and passive [22]; many people are just lurkers, using the information but not participating by generating content or contributing to WOM.Nevertheless, the engagement in virtual brand communities is more complex, having multilayered motivations and displaying many behaviors: helping other members, manifesting a sense of belonging, participating in group activities, and socializing.
WOM recommendations from friends and family occupy the third place in the top sources of brand discovery, after search engines and TV advertisements: 28.5% of Internet users develop an awareness of brands and products through WOM [155].This statistic emphasizes the continuing shaping role of WOM even in an increasingly online-wired world.WOM is efficient in influencing people's behaviors and more productive in comparison with traditional marketing strategies [156].WOM (positive and negative) has been found to impact several key elements such as consumer choice, purchase decision, and perception of the brands [157,158].When a brand is loved, the chances that a person will recommend it are very high [159].Talking about cosmetic products or making recommendations to friends are very efficient persuasive strategies in the cosmetic area.Generally, customers pay more attention to WOM because it is perceived as credible and generated by people (friends, family, or even anonymous users) who are assumed to have no self-interest in promoting a certain brand, not the company.The personal experience with a brand that directly addresses different body segments and needs is valued because it is perceived as filling a piece of "missing" information related to the "real" performances of the product [160].The customer-to-customer communication also represents a form of validation because people test the acceptability of their decisions through social comparison with close friends and family, and the probability of deciding the same as them is large [142].Cosmetics are classified as "experience goods", so the pre-consumption phases become important for awareness, information, and learning [32].Among factors that influence most consumers' attitudes about high-end cosmetics, WOM and perceived quality are very significant [161].The importance of WOM is higher in the case of new cosmetic products that have never been experienced before.WOM reduces the uncertainty of decision-making, consolidating the reputation evaluation [162].The willingness to recommend cosmetic products to others is higher when their quality is superior and customer satisfaction is accomplished.For instance, the term "green WOM" refers to the positive reference made by others regarding brands' environmentally good practices [163].
People want to share their opinions (good or bad) about cosmetic brands via different channels and media.In a world with 5 billion Internet users, meaning 63% of the total population [155], it is expected that individuals want to be connected online with brands and other consumers.Moreover, the third way of interacting with a brand is following it on a social network, and 22.4% of Internet users perform this behavior.Additionally, 75.4 % of people use social media for research about brands and products, while 22.1% use social media to find "like-minded communities and interest groups" [9,155,164].Therefore, we hypothesize that: Hypothesis (H 11 ): Word-of-Mouth has a positive influence on Intention to Join an Online Brand Community.
Based on these arguments, within the Stimulus-Organism-Response model, we propose the conceptual model displayed in Figure 1.

Research Design, Sampling, and Data Collection
The research aimed to examine the effects of (1) social prestige and the (2) economic, (3) social, and (4) environmental sustainability of the cosmetic brands, which lead to (5) brand attachment and (6) brand attractiveness, finally resulting in (7) WOM, (8) purchase intention and ( 9) intention to join an online brand community.To achieve the research's aim, a quantitative study was conducted through an online questionnaire, with data collected using an online survey platform between May and July 2022.Invitations to participate in this study were disseminated using social media.We utilized a non-probability sampling method, namely snowball sampling [165], because the participants were required to possess a difficult-to-find characteristic: they had to be customers of sustainable cosmetics brands.

Socio-Demographic Profile of Respondents
The final database contained 1632 valid answers, with around 55.39% females and 44.1% males.The respondents were mainly young and middle-aged people between 14 and 50 years old (84.55%).Individuals' income per month was as follows: 56.19% of respondents had a low income-under the minimum income in Romania, 32.97% earned a middle income-between the minimum and the average income, and 10.84% had a high income-above the average income.Occupations were mainly students and employees in enterprises, accounting for 51.41% of the total sample.The details are shown in Table 1.The data obtained from the online questionnaire were analyzed in SPSS 22.0 software, while the structural model from Figure 1 was assessed with SmartPLS [166].The questionnaire was operationalized following the recommendations of Robinson [167], based on different scales adapted from the literature (see Table 2).All statements were measured on a seven-point Likert-type scale ranging from 1-Total disagreement to 7-Total agreement.The constructs (Economic Sustainability-ESU, Social Sustainability-SOS, Environmental Sustainability-ENS, Social Prestige-SP, Brand Attractiveness-BAR, Brand Attachment-BAT, Purchase Intention-PI, Word-of-Mouth-WOM, Intention to Join Online Brand Community-IJOBC) were measured in a reflective nature, and thus the indicators of the latent variable were correlated.These constructs depicted between two and six items each [168].

Assessment of the Measurement Models
To test the conceptual model (Figure 1), SmartPLS 3.0's structural equation modelling approach was utilized.The measures from Table 2 included in the conceptual model had a reflective nature.By relying on PLS-SEM, all relations between the latent variables could be thoroughly analyzed as recommended by the literature [173].For assessing the validity and internal consistency of the considered dimensions, as well as the loadings of all items, the average variance extracted (AVE), the composite reliability (CR), and the discriminant validity several tests were performed (see Tables 3-5).According to the values from Table 3, all loadings exceeded the minimum recommended thresholds of 0.70, so the measured variables were proven to display a proper convergence validity [173], with values ranging between a minimum of 0.700 and a maximum of 0.957.The reliability test was used, and the Cronbach's alpha (α) coefficient was computed for each of the constructs.The value had to be above 0.7 (see Table 3), a level that is acceptable for confirmatory purposes [174,175].As the constructs fulfilled this threshold, we considered the model to be internally consistent.The AVE (see Table 3) values exceed 0.5, which indicates an adequate model [176].This allowed us to support the constructs' convergent validity.The composite reliability (CR) values exceeded 0.7, so the constructs are reliable [173].Discriminant validity was also checked for each construct by relying on the Fornell-Larcker and the Heterotrait-Monotrait criteria, which allows for testing the conceptual similarity of constructs (Tables 3 and 4).Based on both analyses, it was shown that the AVE exceeds the correlation coefficient between the component and the considered variables.The values of the construct are below the recommended threshold of 0.9 [174,175], so discriminant validity is given (Table 3).
In the next step of the procedure [168], the level of collinearity between the variables in the measurement model had to be considered.The VIF values for the items were found to be above 5, which is considered the maximum acceptable threshold when addressing collinearity issues.The highest value is 2.956 (SOS1 item) in the dataset, so there is no multicollinearity between the variables.The next step of the procedure was to employ bootstrap analysis to test the hypotheses and the relationships between the latent variables.Eleven hypotheses were accepted with a significant, positive relationship based on t-statistics.
The evaluation of the structural models To thoroughly assess the structural model, we have also analyzed the collinearity of the constructs.The highest VIF value of the inner model is 3.040 (SOS → BAR), thus below the threshold value, indicating that there is not any multicollinearity between constructs.The goodness of fit of the saturated model is also acceptable.The square root mean residual (SRMR) has a value of SRMR = 0.051, which fulfils the recommended criteria <0.08.
The three dimensions of sustainability, namely Economic Sustainability (ESU), Social Sustainability (SOS), and Environmental Sustainability (ENS), together with Social Prestige explain 39.7% of the variance of Brand Attractiveness (R 2 = 0.397); Brand Attractiveness (BAT) and Social Prestige (SP) count for 49.6% of the variance in Brand Attachment (R 2 = 0.496), while Brand Attractiveness explains 47.3% of the variance of Purchase Intention (R 2 = 0.473).Brand Attachment explains 58.9% of the variance of Word-of-Mouth (R 2 = 0.589).Purchase Intention (PI) and Word-of-Mouth (WOM) explain 52.7% of the variance of the Intention to Join Online Brand Communities (R 2 = 0.527), defining the strong predicting power of the structural model (see Figure 2).

Results and Discussions
The results of the hypothesis testing are presented in Table 5. H1 assumed that Economic Sustainability has a positive influence on Brand Attractiveness.The results attest that this relation is very strong and highly significant, thus H1 is to be supported.This finding indicates that cosmetics brands that demonstrate economic sustainability are

Results and Discussion
The results of the hypothesis testing are presented in Table 5. H 1 assumed that Economic Sustainability has a positive influence on Brand Attractiveness.The results attest that this relation is very strong and highly significant, thus H 1 is to be supported.This finding indicates that cosmetics brands that demonstrate economic sustainability are viewed as more attractive by consumers because they may invest a portion of their profits in innovation initiatives [177] and create an image of successful brands that deliver on their promises over time [70,71].H presumed that Social Sustainability has a positive influence on Brand Attractiveness.The results (see Table 5) pinpoint a very low positive and very moderate significant relation, thus allowing us to confirm H 2 .This finding is consistent with previous research [78,79] and can be explained by the fact that the Social Sustainability dimension is "elusive" or ambiguous for many consumers, even though the "social footprint" of cosmetic brands [21] also serves as a competitive advantage and could influence brand attractiveness for consumers who are familiar with this concept.The social aspects are less visible than the environmental issues [24,34,54] and are also problematic to measure [34,84].
H 3 evaluated the Environmental Sustainability influence on Brand Attractiveness.The results also substantiate a very low positive influence, of low significance.The relationship is to be supported, and H 3 can be confirmed.These findings could be explained by the fact that cosmetic brand consumers have diverse environmental values and concerns [91,141,178].Customers with non-environmentally oriented views may be less sensitive to brands that promote environmental sustainability and find them less attractive.On the other hand, there are significant market segments (e.g., young consumers) that are more aware of the influence of cosmetics goods on the earth and seek environmentally friendly cosmetics [91,141].In sum, the social and environmental dimensions of sustainability are less visible than the economic aspect as drivers for brand attractiveness.One possible explanation is that the respondents concentrated more on the economic dimension of sustainability when they thought about their favorite sustainable cosmetic brands.It is also plausible that the messages transmitted by those respective brands did not bring forward enough social and ecological elements.Moreover, the customers who have already included a strong environmental axis in their life philosophy, for example, may be very sensitive to ecological cues provided by brands, while other consumers ignore them when they assess a cosmetic brand.
H 4 assessed that Social Prestige has a positive influence on Brand Attractiveness.The results prove the strong positive and significant meaning of this influence; therefore, H 4 is supported.This result confirms that cosmetics brands offer status to consumers [102,103] and that the social prestige earned by purchasing and using a certain cosmetic product may positively influence the customer's perception of that brand [22], making it appear more attractive than its competitors.
H 5 assumed that Social Prestige has a positive influence on Brand Attachment.The results (see Table 5) document that the relation between the two constructs is very strongly positive and of very high significance.In this case, H 5 can be supported.Our findings indicate that cosmetics brands that provide social prestige also establish a cognitive and affective bond with customers because they confer social status and social approval and boost the customer's self-esteem [102,179,180].In other words, a link and attachment are created because the cosmetic brand became an extension of the consumer's self [181,182].H 6 hypothesized that Brand Attractiveness exerts a positive influence on Brand Attachment.The results witness that the relationship is strongly positive and very significant, thus H 6 can be accepted.This result suggests that cosmetic brands considered to be attractive are more likely to create a connection with the customer on both an affective and cognitive level, leading to the brand attachment.This mechanism could be explained by customers believing they share the same values and concerns as the cosmetic brand they choose, and a similarity occurs between their identity and the brand's identity [110,181,183].H 8 supposed that Brand Attachment has a positive influence on Word-of-Mouth communication.The results confirm that the relation between these two constructs is positive and highly significant; therefore, H 8 is to be accepted.The finding indicates that the bond between customers and the cosmetic brand they choose is a form of attachment that predicts favorable word-of-mouth and a willingness to promote the brand to others [119].H 7 predicted that Brand Attractiveness exerts a positive influence on Purchase Intention.The results pinpoint the very strong and highly significant influence of Brand Attractiveness on the Purchase Intention of cosmetics.This allows us to also accept H 7 .This result implies that the brand attractiveness of cosmetic brands is an important prerequisite of customers' willingness to buy, as the brand is perceived as desirable and compatible with potential customers [29,30].
H 9 postulated that Purchase Intention has a positive influence on Word-of-Mouth communication.The results (see Table 5) demonstrate that this impact is of high and strong positive influence, so that H 9 is to be validated.One possible explanation for this result is that the consumers exhibiting purchase intent are attracted, attached, and even in love with the brand [159].These antecedents drive individuals to perceive the sustainable cosmetic brand as a great deal and be prepared to spend money on it [30,32].This positive perception may result in recommending the cosmetic products to others, thereby boosting Word-of-Mouth communication [158].
H 10 posited that the Purchase Intention has a positive influence on Intention to Join Brand Online Community.The results indicate a low influence with a moderate significance, thus H 10 can be partially confirmed.This result can be understood by having in mind the broader process of the consumer decision process.The intention to join the brand community, even in an online environment, probably also depends on consumer satisfaction that occurs in the post-purchase phase [145,184].This means that individuals need to assess the value of the brand and become satisfied with its consumption.If, in this post-purchase phase, the brand fails in fulfilling expectations, the customer will probably be dissatisfied and not join the brand community, thus not becoming a fan of the brand.
H 11 ascertained that Word-of-Mouth has a positive influence on Intention to Join Brand Online Community.The results confirm the strong positive and significant meaning of this influence; therefore, H 11 can be supported.This significant observation can be explained by the fact that customers who promote the sustainable cosmetic brand seek to reinforce their ideas and validate their thoughts by sharing them with similar customers.Positive Word-of-Mouth regarding sustainable cosmetic brands provides vital information to clients and potential customers, fosters a community feeling, and reunites individuals that share an interest in brand products and activities [185,186].This results in the formation of a consumer community in the online environment.Customers join the brand community for amusement, networking, evaluations, a sense of identity and integration, the pursuit of status, and even to co-create brand narratives [184].

Conclusions
From a theoretical perspective, our research contributes to extending studies based on the SOR approach applied to sustainable cosmetics brands by also considering important variables, such as social prestige and the intention to join an online brand community.The proposed conceptual model contributes to the sustainable literature by confirming the impact of the three pillars of TBL (i.e., economic, social, and environmental sustainability) (stimuli) on brand attachment and brand attractiveness (organism), which finally results in WOM, purchase intention, and intention to join an online brand community (response).This valuable theoretical and practical framework based on SOR can enhance our understanding of the customer perception of sustainable cosmetic brands.The results highlight that, alongside the TBL, social prestige is another important antecedent that generates brand attachment and attractiveness.This unique insight of our research could be useful for brand managers to promote their sustainable brands in the online environment, and to create online communities where brand fans sharing the same brand values can find relevant information, discuss products and brand environmental initiatives, and even purchase products.
From a managerial perspective, these results have important implications because TBL is a modern business paradigm and is widely used in consumer behavior research because it can explain the factors involved in the decision-making process.Cosmetic brand managers need to develop strategies to improve economic, social, and environmental sustainability due to the important outcomes of these three variables regarding consumer perception and intentions.Cosmetics represent an industry with changing general trends that try to align with sustainable principles and practices.Although the customers are still quite diverse, many expect cosmetic brands to commit to a sustainable agenda.Brand managers who adopt a sustainable business strategy could also be proactive in preventing brand crises caused by using chemical substances, the unethical procurement of natural ingredients, pollution, environmental disasters, packaging composition, and safety concerns about their products.
Several limitations of the research should be examined when considering future studies.The research was conducted in a single market, so the findings cannot be extrapolated to other social circumstances, and the results must be interpreted within a specific cultural context.Future studies should concentrate on validating the proposed model in different geographical and/or cultural regions around the globe (i.e., EU, China, USA, Russia, India, etc.).This could lead to the opportunity to conducting cross-cultural studies and comparing the results among different markets.
The conceptual model has been evaluated for sustainable cosmetic products.Future research could replicate the model by comparing environmentally friendly with nonenvironmentally friendly brands, as well as by studying brands in various industries (food versus non-food, fashion versus electronic articles, etc.).We used participant self-reports to measure the variables in our study.This measurement method has some inherent drawbacks, including honesty (subjects might give the answer that would be more socially acceptable rather than the truth) and introspective ability (subjects might not be able to accurately evaluate themselves).These limitations are often found in consumer behavior research, particularly when it pertains to a socially desirable phenomenon, such as sustainability.Additionally, the respondents' answers are limited to their opinions and intentions regarding their purchase intentions, word-of-mouth, and intentions to join online brand communities.Acquiring information about their actual consumption and purchase patterns could lead to different results.
The study was conducted using a non-probability sample and may not be representative of the overall population of users of brand-name cosmetics.Future research could test the proposed model using probability sampling, for instance.As the data were collected in a cross-sectional study, we could not analyze the evolution of the studied phenomena.Therefore, future studies could focus on conducting longitudinal studies and performing more advanced data analysis.In addition, the conceptual model could be expanded in future studies by incorporating other dimensions, such as sociodemographic characteristics (age, level of education, income) and consumer hedonic values, thus also pinpointing generational differences between Millennials, Baby Boomers, Xers, or Zers.An interesting perspective would be to compare the brand perceptions of green and/or sustainable cosmetic brands with traditional ones.

Figure 1 .
Figure 1.Prerequisites of Purchase Intention, WOM, and Joining Online Community of Sustainable Cosmetic Brands.Source: own development.

Figure 1 .
Figure 1.Prerequisites of Purchase Intention, WOM, and Joining Online Community of Sustainable Cosmetic Brands.Source: own development.

Hypothesis (H 9 ):
Purchase Intention has a positive influence on Word-of-Mouth.Hypothesis (H 10 ): Purchase Intention has a positive influence on Intention to Join an Online Brand Community.2.7.The Intention to Join the Online Brand Community and the Word-of-Mouth (WOM)

Figure 2 .
Figure 2. Structural model: Prerequisites of Purchase Intention, WOM, and Joining Online Community of Sustainable Cosmetic Brands.

Figure 2 .
Figure 2. Structural model: Prerequisites of Purchase Intention, WOM, and Joining Online Community of Sustainable Cosmetic Brands.

Table 1 .
Demographic characteristics of the survey participants.

Table 2 .
Constructs and items.

Table 3 .
Cronbach Alpha, Composite Reliability, Average Variance Extracted and Discriminant validity analyses with the Fornell-Larcker criterion.

Table 5 .
The path coefficients of the structural equation model.