The Effect of Service Marketing Mix on Relationship Quality and Revisit Intentions for Korean Restaurants in Vietnam

Abstract

The purpose of this study is to find out how service marketing mix affects relationship quality and revisit intention. Additionally, this study examines whether there was a moderating effect according to the country of origin among constructs. In order to measure the service marketing mix, seven factors were considered such as food, price, location, promotion, physical evidence, service process, and employees. For empirical analysis, data was collected by utilizing surveys of Korean and Vietnamese consumers who frequented Korean restaurants in Hanoi, Vietnam. The data were analyzed by using SPSS 24 and the AMOMS 24 program. Confirmatory factor analysis (CFA) as well as a structural equation model (SEM) analysis were performed. The results of the empirical analysis showed that, first, the factors of service marketing mix such as food, price, location, physical evidence, and service process had a significant positive effect on relationship quality. Second, relationship quality had a significant positive effect on revisit intention. Third, it was found that where was a significant moderating effect depending on the consumers by country between these constructs.It could be observed that food, location, and promotion had a significantly effect depending on the nationality of consumers. Therefore, the research hypotheses formulated were sufficiently supported by the results.

1. Introduction

Recently, Vietnam has witnessed a rapid social and economic development, maintaining 6–7% economic growth, in part because of the open market policy and abundant labor force. With the average population age of 30, this young generation is leading the consumption market in Vietnam, with increases in food consumption and material abundance due to the open market policy and globalization (Kotra, 2020). Vietman’s food service industry showed a value of $23.4 billion in 2018, which has since increased annually by 7.8% from 2014 to 2018. In 2018, the total number of Vietnamese restaurants was 317,741, and these could be subcategorized into full-service restaurants, quick-service restaurants, cafes and pubs, street vendors, and stalls. Full service restaurants can be described as high-end restaurants that serve high-priced and high-quality food. A quick service restaurant is a fast-food restaurant that includes ice cream specialty stores, bakeries, and convenience stores. The total sales of full-service restaurants account for 71.1% of the total Vietnamese food service industry, showing a high annual growth rate of 9.5% (Ho Chi Minh Branch of the KITA, 2019).

Vietnam’s food service industry is expected to grow at a steady rate, in part due to the increase in disposable incomes of households, the consumption trend for convenience, the popularity of the tourism industry, the expansion of food delivery services, and the development of the food service culture. A number of local F&B companies are leading the quantitative and qualitative growth of the Vietnamese food service market by purchasing local business franchises of foreign food brands or expanding restaurant stores through the development of their own brands. In particular, shopping malls are garnering attention as a major location for locals to eat out with their interest in Asian foods and location that offer high quality at low prices such as buffet restaurants, hot pot places, and Korean BBQ (Kotra Hanoi, 2018).

In Vietnam, the number of Korean restaurants is increasing at a remarkable pace, as well as consumption of Korean foods, mainly due to the influence of the Korean Wave brought by K-dramas and K-pop. As of 2017, there were a total of 528 Korean restaurants in Vietnam, which is a 160.1% increase from 203 in 2014 (Korean Food Promotion Agency, 2017). Korean food is one of the most preferred foreign cuisines by Vietnamese consumers, with kimchi being the most popular dish. Following kimchi, in order of popularity, is kimbap, tteokbokki, bibimbap, and bulgogi. Recently, cheese buldak and pork belly have also been increasing in popularity (Ho Chi Minh Branch of the KITA, 2019).

Meanwhile, starting new restaurants in the Vietnamese food service market is becoming increasingly fierce. This is in part due to the insufficient store location, as well as intensifying competition with existing restaurants, and an increasing demand for the consumer’s diverse tastes. Because there are many cases of failure of restaurants attempting to enter the food service market solely based on Vietnam’s market potential, there has been a growing need to systematically survey the demand of the local consumers’ tastes beforehand (Kotra Ho Chi Minh, 2016). In order for Korean restaurant brands to succeed in Vietnam, there needs to be menus that reflect the local food culture, as well as prices that are consumer-friendly (Ho Chi Minh Branch of the KITA, 2019). Moreover, for the continuation and growth of the local Korean restaurants, strategic service marketing activities that reflect the demands of local customers, as well as building of close relationships, are needed. In line with this, it is imperative that Korean restaurants become knowledgeable about the details of the local consumers and marketing activities, but research on this has been relatively lacking.

The Vietnamese people has a different lifestyle culture than Koreans, so differentiated service marketing activities are needed. It is an important factor to analyze the various preferences of Korean and Vietnamese consumers and identify any of their differences in order for the Korean restaurants to provide satisfaction and expand their consumer relationships. Thus, efforts are needed to analyze and identify local consumer needs for Korean restaurants, as well as establish strategies to satisfy those needs, not to mention maintain and expand customer relationships.

This study aims to study the behaviors of consumers in Korean restaurants located in Vietnam, as well as measure the service marketing mix, relationship quality, and revisit intentions, among others, for consumers in Korean restaurants. The difference in needs between Korean and Vietnamese consumers will also be observed, as well as its implications in this research context.

2. Theoretical Background

2.1. Service Marketing Mix

Marketing is a process in which a company creates value for its customers and builds strong customer relationships, in return for obtaining the correlating value from its consumers (Kotler & Armstrong, 2010). Marketing is categorized into two fields, manufacturing and service, and is classified into two categories: manufacturing-oriented tangible goods and service-oriented intangibles. Marketing studies on services has been extensively studied due to the ever-changing social norms since the 1980s, and the scope of marketing research on services has been expanded with the introduction of the PZB model that measures service quality (Parasuraman, Zeithaml, & Berry, 1988). This is also due to the transition from an economy that had been a manufacturing-oriented economic environment to a service-oriented economic environment. Due to the economic development, demand for services such as management consulting, market research, and technical education has increased, and businesses that specialize in services such as finance, information processing, insurance, and computer-related businesses have diversified. Furthermore, in the manufacturing sector, service-related marketing strategies are needed due to the intensifying market competition. The combination of variables for establishing such a marketing strategy is called a marketing mix. Marketing mix is defined as a unique combination of factors that are able to meet and provide customer needs. In other words, the marketing mix can be said to be a set of tools used by a company to achieve marketing goals in a target market (Kotler, 1997).

As such, research on service marketing has been widely conducted due to the expansion of the service market (Lovelock, Wirtz, & Chew, 2009). The traditional manufacturing-oriented marketing mix consists of the marketing strategies in four main areas: product, price, location, and promotion. In the early days, it was argued that the marketing mix, which was a strategy devised for the manufacturing industry, was not suitable for service marketing. This was because the service marketing had its own unique characteristics. Based on this, scholars have since improved the existing marketing mix to derive a new service marketing mix element to match the service company and its needs. But, the service marketing mix is limited to the traditional marketing mix, so an extended form of the service marketing mix (7Ps) was proposed as an extension of the existing 4Ps (Lovelock & Wirtz, 2007; Zeithaml & Bitner, 2003).

Service companies such as the food service industry are in great need to utilize various and intensive service marketing mixes because they have to use controllable resources while at the same time being able to appropriately adapt to a difficult corporate environment to satisfy the needs of the target market. The components of the service marketing mix are described by many researchers as mainly consisting of product, price, location, promotion, employees, physical evidence, and service delivery processes, that is, the 7Ps (Booms & Bitner, 1981; Zeithaml & Bitner, 2003).

Regarding the food industry, domestic studies using 7Ps have been carried out. Yoon (2010) conducted a study on the service marketing mix and customer value of family restaurants, and studied the marketing mix by suggesting seven elements such as food, price, location, promotion, process, physical evidence, and employees. Han and Lee (2012) conducted a study on the service marketing mix for the service system of coffee specialty stores. Shin, Kim, and Chung (2014) conducted a study utilizing service marketing mix as an influencing factor of wine bar images, and presented the marketing mix elements as seven factors including product, price, promotion, place, staff, physical environment, and processes. Kim and Lee (2017) conducted a study on hotel package products using the Kano model, and studied the marketing mix by presenting seven elements: product, price, route, promotion, people, physical evidence, and processes.

In this study, service marketing mix will be considering seven factors, namely, food, price, location, promotion, physical evidence, service process, and employees.

2.2.Service Marketing Mix and Relationship Quality

Relationship quality is defined as customer evaluation from a long-term perspective as the ability of employees, the final contact point of service, to reduce the perceived uncertainty of customers (Crosby, Evans, & Cowles, 1990; Sasono, Jubaedi, Novitasari, & Wiyono, 2021). Morgan and Hunt (1994) described relationship quality as all marketing activities directly connected to the exchange, establishment, development, and maintenance of successful relationships. Kim and Cha (2002) defined relationship quality as customer perception and evaluation of communication between service providers and customers.

Relationship quality has been studied in various aspects from the perspective of consumers, targeting the relationship between service companies and customers, salespeople and customers, manufacturers and distributors, and suppliers and resellers. In studies on relationship quality, various constituent factors are presented (Oh & Kim, 2009). Regarding the measurement of relationship quality, existing studies mainly identify three factors, such as trust, satisfaction, and commitment, or only a few of these. Studies defined the constituent factors of relationship quality as satisfaction and trust (Cheng, Chen, & Chang, 2008; Chun & Park, 2011; Crosby, Evans, & Cowles, 1990; Kim & Cha, 2002; Yin, 2002), trust and commitment (Bitner, 1995; Morgan & Hunt, 1994), and satisfaction, trust, and commitment (Roberts, Varki, & Brodie, 2003; Shin, Kim, & Chung, 2014). There are various opinions regarding the relationship between trust and satisfaction, and the cause- and-effect relationship of commitment, but in general, it was confirmed that satisfaction precedes trust in the relationship between trust and satisfaction (Crosby, Evans, & Cowles, 1990). Therefore, in this study, based on previous studies such as Crosby, Evans, and Cowles (1990), the quality of relationship with customers was premised on the relationship between restaurant specialty stores and customers, and the degree of satisfaction and trust that customers perceive in restaurant specialty stores was considered as a complex interlocking concept.

In various studies in the service area, the correlations with relationship quality was observed, such as research related to franchise headquarters and affiliated stores (Han & Yu, 2010), research on performances and events (Hwang, 2018; Yoo, 2016), research on beauty (Park, 2017; You, 2018), research on tourism and aviation (Ko & Han, 2014; Sim, 2014), and studies releated to the food industry (Lee & Kim, 2015; Park & Lee, 2016; Shim, 2014). In studies related to the restaurant franchise, the relationship between the service marketing mix element of the headquarters and the relationship quality was structurally analyzed. In performance events, the marketing mix of the subject and the satisfaction and reliability of the participating companies were evaluated. In tourism and aviation related research, the relationship between service marketing mix and satisfaction and reliability was studied for customers who use airline services, local tourist attractions, fairs, and ski resorts. For studies on the food industry, the relationship between marketing service mix, satisfaction and reliability was studied for customers who use wine bars, chicken specialty stores, and franchise coffee specialty stores. As such, research in various fields reveals that the service marketing mix factor has a positive effect on relationship quality.

Based on these preceding studies, the following hypothesis was formulated under the premise that the service marketing mix of Korean restaurants in Vietnam had a significant effect on relationship quality.

H1: The service marketing mix of Korean restaurants will have a significant positive (+) effect on relationship quality.

H1-1: The food of the Korean restaurant will have a significant positive (+) effect on relationship quality.

H1-2: The price of the Korean restaurant will have a significant positive (+) effect on relationship quality.

H1-3: The location of the Korean restaurant will have a significant positive (+) effect on relationship quality.

H1-4: The promotion of the Korean restaurant will have a significant positive (+) effect on relationship quality.

H1-5: The physical evidence of the Korean restaurant will have a significant positive (+) effect on relationship quality.

H1-6: The service process of the Korean restaurant will have a significant positive (+) effect on relationship quality.

H1-7: The employees of the Korean restaurant will have a significant positive (+) effect on relationship quality.

2.3. Relationship Quality and Revisit Intention

In various studies related to service marketing, revisit intention was applied as a variable of outcome behavior. This can be interpreted as the positively-formed relationship quality that induces a favorable revisit intention. In research relating to distribution, studies related to hotel reservation channels (Kim, 2019) and those relating to the use of mobile applications (Park & Yoon, 2019) revealed that relationship quality has a positive effect on the reuse intention as a resulting behavior. In research related to performances and events, those on MICE experience (Lee & Kim, 2013) and exhibitions (Kim & Lee, 2015) revealed that relationship quality has a positive effect on the intention to revisit by consumers. In a study related to the food industry, the service quality measurement of a Korean restaurant targeting Japanese tourists revealed that if the relationship quality such as satisfaction and trust is high, the intention to revisit by consumers can be increased (Cheon & Kim, 2013; Ilyas, Rahmi, Tamsah, Munir, & Putra, 2020). In a study that measured the service quality of Korean restaurants with Chinese medical tourists, it was found that the quality of relationship had a large positive effect on the behavioral intention, which was considered to be the outcome behavior (Oh & Yoon, 2018). A study on service quality measurement of Japanese restaurants (Song & Jung, 2014), and on the measurement of service quality in hotel restaurants (Koo & Han, 2019), as well as a study of relationship benefits and relationship quality of Korean food franchises (Lee & Kim, 2018) revealed that the relationship quality formed by satisfaction and trust had a positive effect on behavioral intention.

As such, the main variables of behavioral intention in various studies have been suggested to be revisit intention, re-use intention, recommendation and solicitation, and positive word of mouth.The research on relationship quality and behavioral intention entails that the consumer’s attitude toward re-visit intention or re-use intention is working positively in relationship quality. Thus, various studies have also examined that relationship quality has a significant relationship with revisit intentions for consumers. In this study, the following hypothesis was established under the premise that the relationship quality at Korean restaurants will have a positive causal relationship with the intention to revisit for consumers.

H2: Relationship quality will have a significant positive (+) effect on revisit intention.

2.4.Moderating Effect Among Consumer Groups by Country

This study aimed to understand the consumer behaviors targeting Korean restaurants in Vietnam. The relationship between these research concepts was structurally designed under the premise that the service marketing mix of Korean restaurants will affect the relationship quality and revisit intention of the consumers (Kim & Yang, 2020). In the context of this research, since this is a Korean restaurant located in Vietnam, the diversity of the consumers by nationality will inevitably emerge as well. Therefore, in this study, it can be premised that there will be a difference in consumption behavior between Korean and Vietnamese consumers residing in Vietnam. Therefore, in the research model, the hypothesis was established as follows on the premise that there is a moderating effect among consumer groups by country in the structural relationship of these research concepts.

H3: There will be a significant moderating effect among consumer groups by country in the structural relationship between the service marketing mix and relationship quality, and revisit intention.

3. Methodology

3.1. Research Model

The purpose of this study was to investigate the effect of the service marketing mix of Korean restaurants on relationship quality and revisit intentions, as well as measure the moderating effect of Korean consumers and Vietnamese consumers in the relationship between these research concepts. A research model was designed for this, as shown in Figure 1. The service marketing mix presented seven mix factors (7Ps) including food, price, location, promotion, physical evidence, service process, and employees.

Figure 1: Research Model

3.2. Sample Design and Analysis Method

This study surveyed Korean and Vietnamese consumers from 32 Korean restaurants in Hanoi, Vietnam, from December 1 to December 31, 2019, using the direct survey method or a simple random sampling method online. Excluding no-responses and non-valid responses in the collected data, a total of 457 surveys of valid samples (205 Korean surveyed and 252 Vietnamese surveyed) were used for empirical analysis.

The data were analyzed utilizing SPSS 24 and AMOS 24 programs. To verify the validity of the measured variable, a confirmatory factor analysis (CFA) was performed, as well as a structural equation model (SEM) analysis to investigate the relationship among constructs. To confirm the model is fit for this, verification statistics such as χ², RMR, GFI, AGFI, RMR, NFI, and CFI were applied. Additionally, a multi group analysis using the χ² difference test was conducted to verify the moderating effect of consumers by country in the relationship among constructs.

3.3. Measurement of Variables

A total of nine multi-item measurement concepts, including seven service marketing mixes, relationship quality, and revisit intentions, were selected and utilized for this study.

Service marketing mix is defined as a set of tools or methods used by service companies to achieve marketing goals in their target market. The service marketing mix scale used in this study was based on studies conducted by Han and Lee (2012), Lovelock, Wirtz, and Chew (2009), Kim and Lee (2017), and Shin, Kim, and Chung (2014), among other researchers. It consisted of a total of 28 items out of the seven factors such as food, price, location, promotion, physical evidence, service process and employees. These factors were measured using a five-point scale, from 1 = not at all to 5 = strongly agree.

Relationship quality was defined as the customer perception and evaluation of service providers formed through their transaction experiences. The relationship quality scale was defined as the degree of satisfaction and trust that customers perceived in restaurants based on studies conducted by Cheng, Chen, and Chang, (2008), Chun and Park (2011), and Park and Kim (2011), to mention a few. The relationship quality scale consisted of four items and was measured using a five-point scale from ‘1 = not at all’ to ‘5 = strongly agree’.

The intention to revisit was defined as revisiting the store after experiencing the restaurant service. The measurement of the revisit intentions was composed of three items based on research by Koo and Han (2019), Lee and Kim (2018), and Oh and Yoon (2018). This was also measured using a five-point scale from ‘1 = not at all’ to ‘5 = strongly agree’.

4. Results and Discussion

4.1. General Characteristics

This study evaluated the demographic characteristics of 205 Korean and 252 Vietnamese consumers, for a total of 457 people.

The characteristics of the Korean people samples in this study were shown to consist of 99 males (48.0%) and 106 females (52.0%). The age group consisted of 48 people under 40 years of age (23.7%), 58 people between the ages of 41 to 50 (28.5%), 55 people between the ages of 50 to 60 (27.1%), and 42 people over the age of 61 (20.8%). The occupations for the Korean sample included 48 people as full-time housewives (42.6%), 89 people as office workers (23.0%), 30 people as self-employed (14.4%), 27 people as working professionals (12.9%), and 11 as others (5.6%). The average monthly income showed to be 43 people earning 4 million won or less (23.4%), 50 people earning between 4 to 5 million won (27.1%), 53 people earning between 5 to 8 million won (28.8%), and 37 people earning over 8 million won (20.7%). It was also shown that the Korean restaurants that Korean people enjoyed the most were Old Palace (34 people), Meat Plus (20 people), Buttomok, Sodam (16 people), Biwon (14 people), Gangnam Myeonok (13 people) and Cheonghakgol (10 people), in this order.

The characteristics of the Vietnamese people samples in this study were shown to consist of 78 males (31.5%) and 173 females (68.5%). The age group consisted of 89 people under 25 years of age (35.7%), 66 people between the ages of 26 to 30 (26.3%), 71 people between the ages of 31 to 40 (28.0%), and 23 people over the age of 41 (10.0%). The occupations for the Vietnamese people included 119 people as office workers (46.1%), 44 people as students (17.1%), 33 people as government workers (12.8%), 32 people as self-employed (12.4%), and 24 as others (9.5%). The average monthly income showed to be 22 people earning 5 million dong or less (10.2%), 75 people earning between 5 to 10 million dong (30.8%), 23 people earning between 10 to 15 million dong (9.4%), and 54 people earning between 15 to 20 million dong (22.1%), and 67 people earning over 20 million dong (27.5%). It was also shown that the Korean restaurants that Vietnamese people enjoyed the most were King BBQ (60 people), Korean BBQ Center (53 people), Don Chicken (23 people), Meat Plus (24 people), Old Palace (11 people), Mr. Chicken Ribs, and Two Meals (9 people).

4.2. Confirmatory Factor Analysis

Confirmatory factor analysis (CFA) was performed for each measurement item to confirm the relationship among constructs. The confirmation factor analysis is conducted to confirm whether the measurement model is theoretically appropriate. Table 1 shows the results of centralized validity, which is the degree of confluence between the observed variables that measure the latent variables, and Table 2 presents the results of the discriminant validity, which shows the degree of difference between the miscellaneous variables. In the results of intensive validity on Table 1, the overall conformity index was evaluated to derive the optimal conditions for the research model in this study. The results of the identification factor analysis for all research units were χ² = 845.520 (df = 398), p = 0.000, χ²/df = 2.124, RMR = 0.046, GFI = 0.892, AGFI = 0.866, NFI = 0.928, CFI = 0.960, and RMSEA = 0.050, showing that the indices excluding the p-value met the criteria for evaluating model conformity (Jöreskog & Sörborm, 1993). Moreover, the CCR (composite construct reliability) and average variance extracted (AVE) values of the research concepts were calculated in order to evaluate whether the scales used in this study were representative of the research concepts. It was shown that the evaluation criterion, confidence coefficient (CCR), exceeded 0.7 and that the variance extraction (AVE) exceeded 0.5 (Bagozzi & Yi, 1988).

Table 1: Confirmatory Factor Analysis for Constructs

χ² = 845.520 (df = 398), p = 0.000, χ²/df = 2.124, RMR = 0.046, GFI = 0.892, AGFI = 0.866, NFI = 0.928, CFI = 0.960, RMSEA = 0.050 *p < 0.001. a AVE (average variance extracted). b CCR (composite construct reliability: ρc) = (Σ|λi |)2 / {(Σ|λi |)2 + Σθεi }.

Next, the results of the discrimination validity are shown in Table 2. The discriminant validity was shown to be established since the average variance extraction (AVE) value on the diagonal was greater than the square value of the correlation coefficient. Additionally, the validity verification rule shows whether the relationship of the variables in the correlation table is in a positive direction or in the negative direction in terms of significance. In this study, it was seen that the variables were in the positive direction, demonstrating that the results were significant

Table 2: Validity of Constructs

*p < 0.01; Diagonal value: AVE, Parenthese s( ): Squared value of correlation coefficient.

4.3. Verification of the Research Hypothesis

As a result of verifying the overall model of this study, it was shown that an optimal model with χ² = 867.881(df = 405), p = 0.000, χ²/df = 2.143, RMR = 0.047, GFI = 0.890, AGFI = 0.866, NFI = 0.926, CFI = 0.959, RMSEA = 0.050 was derived.

4.3.1. Hypothesis Verification

This study aimed to identify the cause-and-effect relationship between relationship quality and revisit intention in the service marketing mix of Korean restaurants in Vietnam. Also, it was seen whether there was a moderating effect between the Korean and Vietnamese consumer groups. To confirm the relationships between these research concepts, the structural equation model analysis and multi group analysis were conducted.

First, a structural equation model analysis was examined to figure out the effect of the service marketing mix on the relationship quality and revisit intention, and the results are shown in Table 3. As a result of verifying the hypothesis that the service marketing mix will have a significantly positive effect on relationship quality, it was seen that food, price, location, physical evidence, and service process had a positive effect on relationship quality. Of these relationships, it was observed that food (path coefficient = 0.335, t value = 6.824, p < 0.001) had the greatest impact. Next, employees (path coefficient = 0.263, t-value = 5.885, p < 0.001), physical evidence (path coefficient = 0.215, t-value = 5.019, p < 0.001), price (path coefficient = 0.102, t-value = 2.780, p < 0.01), location (path coefficient = 0.065, t-value = 2.041, p < 0.05) were shown to have a positive effect. These results imply that food-related variables such as taste, nutrition, menu, and cultural characteristics are the most important factors to consider when eating Korean food in Vietnam. In addition, physical evidence such as employee response to customers, restaurant atmosphere, facilities, and internal environment were important factors. This means that food prices and location, which are environmental factors around the restaurant, were evaluated as important factors in evaluating relationship quality. These research results prove that service marketing mix has a significant cause and effect relationship with relationship quality as revealed in various previous studies (Han & Wu, 2010; Ko & Han, 2014; Lee & Kim, 2015; Shin, Kim, & Chung, 2014; Sim, 2014).

Table 3: Research Hypothesis Verification Result

χ² = 867.881 (df = 405), p = 0.000, χ²/df = 2.143, RMR = 0.047, GFI = 0.890, AGFI = 0.866, NFI = 0.926, CFI = 0.959, RMSEA = 0.050. *p < 0.05; **p < 0.01; ***p < 0.001.

Furthermore, as a result of verifying the hypothesis that the relationship quality will have a significant positive effect on the consumers’ revisit intention, the path coefficient for these relationships was shown to be very high, with 0.987 (t-value = 18.294, p < 0.001), demonstrating a significant positive effect. This entails that the higher the quality of the relationship, such as satisfaction and trust for Korean restaurants, the more positive the consumers’ attitudes will be, resulting in higher revisit intention rates. thus, this study proves that relationship quality has a significant positive influence on revisit intention as also revealed in various studies related to the food service industry (Cheon & Kim, 2013; Koo & Han, 2019; Lee & Kim, 2018; Oh & Yoon, 2018; Song & Jung, 2014).

4.3.2. Analysis of the Moderating Effects of Consumers by Country among Research Concepts

This study aimed to verify the moderating effect of the consumers from various countries in the scope of the service marketing mix of Korean restaurants in Vietnam on relationship quality and revisit intention. In order to verify this, a multi-group analysis using the χ² difference test between the groups was conducted.

Table 4 shows the results of verifying the difference of χ² by models among consumers by their countries. The moderating effect was verified through the amount of change (Δχ²) of the χ² value of the free model and the constraint model. As a result of the χ² difference test, it was observed that when the degree of freedom was 8 in the amount of change (Δχ² = 17.389) in the χ² value calculated from the free model (1384.926, df = 810) and the χ² value calculated from the constraint model (1402.315, df = 818), the significance level of 5% was greater than the standard value of 15.51, showing a statistically significant moderating effect in the difference between models depending on the consumers by country.

Table 4: Model Comparison by Country (χ² difference test)

*Δχ²: Δ d.f. = 8, Statistically significant greater than 15.51 at a significant level of 5% (p < 0.05); **p < 0.05.

In Table 5, the χ² difference test was conducted to verify the moderating effect through the difference in the path coefficient of consumers by country. By fixing the factor loads of each of the eight paths in the structural equation model of this study (Δdf = 1), we investigated whether Δχ² was 3.84 or higher for each path. As a result, it was observed that there were significant differences among consumers by country in the effects of food, location, and promotion on relationship quality, as well as in the effect of relationship quality on revisit intentions. In the case of food (Korean consumer = 0.408, Vietnamese consumer = 0.222, moderating effect = 0.186) and location (Korean consumer = 0.099, Vietnamese consumer = –0.041, moderating effect = 0.140), Korean consumers were seen to have a relatively larger impact in terms of relationship quality in this regard compared to the Vietnamese consumer counterparts. But, promotion (Korean consumer = –0.051, Vietnamese consumer = 0.038, moderation effect = –0.089) showed to have a greater impact on relationship quality for Vietnamese consumers than Korean consumers. This entails that in terms of food and location, Korean consumers have a relatively positive response to relationship quality, whereas promotion fosters positive responses for Vietnamese consumers. In addition, it was discovered that Vietnamese consumers had a relatively greater influence than Korean consumers in the relationship between relationship quality and revisit intention (Korean consumers = 0.918, Vietnamese consumers = 1.119, moderating effect = –0.201). This can be interpreted to mean that relationship quality consisting of satisfaction and trust acts as an important factor in revisit intention, more so for Vietnamese consumers than their Korean consumer counterparts.

Table 5: Difference in Path Coefficient by Gender

*p < 0.05, **p < 0.01, **p < 0.001.

5. Conclusion and Implications

This study analyzed how the service marketing mix of Korean restaurants in Vietnam affected the relationship quality and revisit intentions of the consumers, as well as the moderating effect of these research concepts according to the consumers by countries. The results of the empirical analysis and implications for these research hypotheses are as follows.

First, as a result of verifying the hypothesis that the service marketing mix will have a significant positive effect on relationship quality, it was seen that food, price, location, physical evidence, and service process had a significant positive effect on relationship quality. This entailed that the taste, menu, and cultural characteristics of Korean food were some of the most important factors for Korean restaurants in Vietnam. Moreover, physical evidence such as employee response to customers, restaurant atmosphere, facilities, and internal environment are important factors for the consumers, and this implies that food prices and location, which are environmental factors around the restaurant, are evaluated as important factors in assessing relationship quality. Based on these results, Korean restaurants in Vietnam should continue to establish social and cultural adaptation strategies.

Second, as a result of verifying the hypothesis that relationship quality will have a significant positive effect on the revisit intention, it was found that this relationship had a significant positive effect. This implies that the higher the quality of the relationship, such as satisfaction and trust, for Korean restaurants, the more positively the consumer attitudes are formed, resulting in a higher intention to revisit the restaurant. Relationship quality is the satisfaction and trust perceived by the consumers, and confers a significant effect for future consumer behavior. Not only that, maintaining a positive relationship with customers is the basis of profit creation. Based on these aspects, there needs to be specific strategic plans that will be create positive consumer results in the future.

Third, as a result of verifying the hypothesis that there will be a moderating effect for each country in the relationship between service marketing mix and relationship quality, as well as relationship quality and revisit intention, there was shown to be a significant moderating effect. This implies that as a new cultural wave of Korean food is taking location in Vietnam, the social and cultural differences are also at work as well. Thus, it would be prudent to establish a marketing mix strategy that incorporates Hallyu culture as well as creating a restaurant atmosphere that reflects the hearts of local customers.

The limitations of this study as well as suggestions for future research are as follows.

First, while this study observed the consumers’ perception of service marketing mix for Korean restaurants in Vietnam, it would also be necessary to conduct research deriving more specific evaluation attributes applicable specifically in Vietnam.

Second, the data was collected using Korean and Vietnamese consumers in Hanoi, Vietnam, but it would be meaningful to expand the scope of research of the overseas expansion of Korean restaurants to target consumers from various countries.

Third, the nature of this study would be better studied as a longitudinal study over a long period of time in order to understand the changing trend of the market and the behavioral patterns of the consumers.