2.1. Industrial Customers’ Satisfaction
Several studies show that the long-term success of an organization is closely related to its ability to adapt to its customer needs and changing preferences [
19,
20,
21,
22]. The analysis of customer satisfaction and its comparison with the results of similar studies can provide policy makers with a unique insight into the motivations and satisfaction of consumers [
23,
24,
25].
Furthermore, customers have access to an educational level that allows them to judge any product or service they pay for, while they demand the best possible products and services at the lowest price. Consequently, a company that meets or even exceeds a customer’s expectations has a significant competitive advantage [
26,
27,
28]. Therefore, it is important for every company to know who its customers are, what they expect and how adequately their expectations are met. This process is of the same importance for both the retail and industrial consumers [
29].
The theory of customer satisfaction has been presented in international literature, as a reliable tool for the evaluation of a company’s results. Customer satisfaction under the view of perceived quality may be seen as the difference between the actual and the expected quality of a product or a service. Many researchers emphasize on satisfaction with functional attributes [
30].
According to Ostrom and Iacobucci [
31], customer satisfaction is a way to evaluate the gap between the expectations of a customer from a particular product or service, and what the customer receives after the use of said product. For the measurement of customer satisfaction certain indexes, price, efficiency or total performance of a company are being used. Woodside et al. [
32], considers customer satisfaction the main factor that affects their behavior. Yi [
33], defines customer satisfaction in two basic ways: either as a result or as a procedure. Furthermore, Yi [
33] considers that the definition of customer satisfaction varies, depending on a series of definitive factors that concern the satisfaction from a product or service, a buying decision experience, a performance attribute, the end-user experience, a company shop or department and, the satisfaction from a pre-buying experience.
Churchill and Suprenant [
6] state that
“satisfaction is the result of purchase and use of a product or service, which derives from the customer’s comparison between the remuneration and the cost of purchase, taking into consideration the expected result”. Customer satisfaction is also based on customer knowledge, which is about products, suppliers and markets [
34].
Kotler [
35], approaching the issue of customer satisfaction from a marketing point of view, has analyzed the meaning of customer satisfaction as feelings of pleasure or discontent, which can be derived from the comparison between the performance or the result of a product or service, and the expectations the person developed before paying for it.
In recent years, it has been widely recognized that customer satisfaction is an essential tool of corporate marketing strategies. According to O’Sullivan and McCallig [
36], customer satisfaction has a positive impact on a firm’s value. The researchers found that this impact is higher than the impact its earnings have on its value. They also found that customer satisfaction positively and significantly moderates the earnings–firm value relationship. Other researchers found that customer satisfaction has a direct and positive effect on customer purchase intentions and loyalty [
37,
38,
39].
Based on the abovementioned analysis, we can conclude that high levels of customer satisfaction can lead to customer loyalty [
40,
41,
42], business profitability [
43,
44], trust [
45], customer retention [
41], positive word-of-mouth [
46,
47], repeating sales [
42,
48], future revenues [
49,
50,
51,
52,
53,
54] increased stock prices [
49,
55,
56,
57], and higher market share [
58,
59].
During recent decades, most researchers on customer satisfaction have focused on satisfaction with consumer goods and services. As far as the satisfaction of industrial customers is concerned, research is still not particularly advanced [
60].
Raj et al. [
61] defines industrial customer satisfaction as a relationship-specific construct, describing how well a supplier meets a customer’s expectation in the following areas: product-related information, services, complaint handling, order handling, product features, interaction with internal staff and interaction with salespeople.
Industrial customers’ satisfaction is closely connected with the quality of the provided products and services provided to them, and is necessary for the continuous improvement and excellence of any company [
62,
63,
64]. As is the case of retail customers, industrial customers’ satisfaction is also connected with the performance of companies and the development of a competitive advantage [
6]. However, industrial customer satisfaction is found to be much more complex [
3].
Homburg and Rudolph [
3] developed a valid customer satisfaction measure for industrial customers, the INDSAT model. The model consists of seven distinct satisfaction dimensions: products, salespeople, product-related information, order handling, technical services, interaction with internal staff, and complaint handling.
2.2. Customer Satisfaction Surveys in Energy Sector
Throughout the last years, several studies have been carried out concerning customer satisfaction with energy providers. Generally, satisfaction in the energy sector covers the quality of a number of services, such as the provision of a new connection, the billing, the handling of customer requests, and complaints. Customer satisfaction can be a significant motivating factor for energy providers. The main objective of an energy organization is to acquire quality products and services that satisfy its customers with measurable improvements to mission capability and operational support in at a fair and reasonable price [
65].
Customers who are satisfied with the service quality they receive, tend to trust their energy provider. Customer satisfaction is a prominent theme in the energy sector. Satisfied customers have the potential to become loyal customers and to attract new customers to an energy provider [
66,
67].
Mutua et al. [
68], formulated a general framework for the study of customer satisfaction in the energy sector (electricity, petroleum, biomass, and renewable energy) in Kenya, using the European Consumer Satisfaction Index (ECSI). They found that customer satisfaction is highest in the renewable energy sector at 74.71%, followed by the petroleum sector at 62.32% and the biomass sector at 61.82%. The electricity sector has the least satisfied customers at 53.06%.
J.D. Power and Associates [
69] conducted a study to measure business customer satisfaction with gas utility companies in four U.S.A geographic regions (East, Midwest, South, and West). This research is based on responses from 10,635 U.S. companies that spend about
$150 per month on natural gas. The study examines six satisfaction criteria; corporate citizenship, billing and payment, communications, price, customer service and field service. The overall satisfaction among business customers of gas utilities averages at 674 on a 1000-point scale.
Moreover, J.D. Power and Associates [
70] using the same set of criteria, measures residential customers’ satisfaction with their gas utility in the same geographic regions in the U.S.A. Retail gas customers were reportedly more satisfied (overall satisfaction 706 index points on a 1000-point scale), than the industrial ones.
Ipsos, London Economics, and Deloitte [
71] conducted consumer market research on the functioning of retail energy markets in the European Union (EU). The research covers all European Union Member States, Norway, and Iceland. Across the European Union countries, 40% of survey respondents “strongly agreed” (scores 8 to 10) that their energy provider offered an overall high quality of service, 40% “agreed” (scores 5 to 7) and finally 15% “disagreed” (scores 0 to 4). In Greece, 30% of survey respondents “strongly agreed”, 41% “agreed” while 26% “disagreed”.
The American Customer Satisfaction Index (ACSI) analyzed customer satisfaction with investor-owned energy utilities serving U.S. residential customers (electric and natural gas service). According the ACSI Customer Satisfaction Reports [
71] the natural gas remains the superlative energy source with an improved score of 78% (100-point scale). The Residential household satisfaction with electricity is lower at 75%.
Liu et al. [
72], developed an evaluation index system of electric power customers’ satisfaction based on the service blueprint theory. The service blueprint model is divided into 4 parts, which are customer behavior, front office staff behavior, back office staff behavior, and support process.
Chodzaza and Gombachika [
73], focused on functional quality offered by the public electricity provider to its industrial customers within Southern Region of Malawi. The findings suggest that the service quality is poor, irrespective of demographic characteristics of the industrial customers. The industrial customers were dissatisfied with the availability of power and customer care services.
Jannadi and Al-Saggaf [
74], conducted a study to measure the customer satisfaction of a typical energy provider in Saudi Arabia. The study revealed that the provider had high satisfaction scores in tangibles dimensions, but low ones in the dimensions of responsiveness and reliability.
Medjoudj et al. [
75], analyzed the customer satisfaction of power users in Bejaia City, Algeria, using the Analytic Hierarchy Process (AHP) method. The obtained results indicate the advantage of investment to improve customer satisfaction and enterprise profitability.
Medjoudj et al. [
75] used three multi-criteria decision making methods (cost benefit analysis, economic criteria inspired from game theory, and the analytic hierarchy process) to find that customer satisfaction with energy providers is expressed by the requirements of high quality of service at the lowest possible cost of electricity.
Ibáñez et al. [
76] proposed a framework where retail customer satisfaction with energy providers is correlated with the dimensions of technical quality of the core services (supply interruption, and service re-establishment), technical quality of the peripheral services (information, consultation, and flexible contracts) and, service process quality (prompt service, politeness, and customer requests). Their results confirmed the direct impact of the examined dimensions on customer satisfaction. Following the same path, Hartman and Ibáñez [
77], proposed a conceptual framework for the impact of satisfaction and switching costs on customer loyalty in energy markets. The main factors related to customer satisfaction according to their analysis are technical quality of the core services, technical quality of the peripheral services, service process quality, value added services, innovations, environmental and social commitment, and pricing policy [
77]. Their results show that in order to increase customer satisfaction with energy providers and thus, indirectly, customer loyalty—service quality should be increased [
77].
Price seems to be important for the industrial customers of energy providers. However, even in this case, it is shown that industrial customers’ satisfaction has an important effect on price tolerance even when switching barriers exist [
78]. This is supported by the finding that even in the case of high switching barriers, they are not big enough to retain dissatisfied industrial customers [
78].
2.3. Natural Gas Market in Greece
The use of natural gas is a strategic choice for the European Union. By using natural gas, the goal is the transition to an economy based on more environmentally friendly sources of energy than oil, while also being the turning point to renewable sources of energy. The above mentioned data can support the fact that natural gas is the second most used type of energy in the European Union, while it takes the third position in world level (
Figure 1).
As already mentioned, after oil (42%), natural gas is the most used type of energy in the European Union (23%). However, Greece is mostly based on oil consumption (66%), while natural gas consumption is equal to 4% of the total energy consumption balance (
Figure 2). This shows that natural gas has a low level of penetration in the Greek market, meaning that there is enough space for growth.
To clearly describe the energy market of Greece, it is notable that the sectors of electricity and natural gas have undergone radical reforms during the last decade towards the full liberalization on the basis of European energy integration. The aim is both the sustainability of the energy system and the security of supply. Another important aspect of these reforms is the creation of conditions for the competitive functioning of the market. The right to choose an electricity supplier for all consumers has been established since 2008. Full liberalization of the natural gas market has also taken place since the beginning of 2018.
Greece fully depends on natural gas imports, with the greater proportion of its supplies coming from Russia, Algeria and Turkey. More specifically, Russian natural gas is 75% of total imports (DEPA). The Public Company of Gas Supply of Greece (DEPA) was found in 1988 and has been the main importer of natural gas pipes and liquefied natural gas (LNG) in Greece ever since. Total natural gas consumption in Greece, seems to follow the established trend of the European Union countries.
Furthermore, according to Eurostat, natural gas prices in Greece follow the average prices of the European Union countries (including taxes and levies) as a decline has been recorded in recent years. More specifically, natural gas prices have decreased from €19.44 in 2012 to €16.41 in 2018 per gigajoule in the European Union countries, while in Greece they have decreased from €28.25 in 2012 to €14.79 in 2018 per gigajoule [
80] (
Figure 3).
Based on data provided by DEPA [
81], the largest part of natural gas in Greece is used for electricity production (55%); industrial customers occupy a big percentage of the total market as their share is about 25%, while 19% of natural gas consumption is for home usage and 1% for vehicles.