“Antecedents of brand advocacy in online food delivery services: An empirical investigation”

Building a solid relationship between a brand and customers has become increasingly prevalent in a firm’s marketing strategy. It has led to a broader and deeper exploration of developing customer relationships by industry practitioners and academic research- ers. Drawing on the marketing literature, this empirical study speculates on the possible mechanism underlying the process of building brand advocacy with consumers in online food delivery services. The data were collected from 562 respondents through online questionnaires from consumers of food delivery platforms in Bangkok and Metropolitan areas, Thailand. The survey data were analyzed using Structural Equation Modeling (SEM) to verify the model. The findings indicated the relationship between customer experience quality (brand experience, service experience, and post-purchase experience), brand leadership (perceived quality, perceived innovativeness, perceived value, and perceived popularity), relationship quality (trust, satisfaction, and commit-ment), and brand advocacy (recommendation, purchase intention, and brand defend- ing). Regarding the investigation, customer experience quality positively affects brand leadership and relationship quality, which, in turn, mediated the pathway from cus- tomer experience quality to brand advocacy. The model explained 72% of the variance in brand advocacy. The study recommends that practitioners consider these findings when designing marketing strategies for online platforms. economy (Vinish Likewise, due to the Covid-19 pandemic, take-away channels and online food delivery (OFD) services via various platforms have become essential for both restaurant business operators and consumers. The competitive direction of the food delivery business remains highly regarded with the consumer trends where many actively use the service. The vast majority of players continue to provide discounts and promotions as an essential competitive tool. However, an accelerated expansion could push the market to get saturation status dramatically (Marketeer Magazine, 2020). Hence, encouraging customers who advocate the brand will be a potential marketing tool to sustain the brand’s standing.


INTRODUCTION
The food industry is often characterized as stable (Thomsen et al., 2014). Nevertheless, the industry is also considered one of the fastest-growing businesses in the global market. Specifically, the food industry evolves through competition and significant challenges in sustaining its competitive position and retaining existing target markets (Firdaus & Kanyan, 2014). Over the last decade, local foods have become popular in the food service and retail industry. Local food can be considered a sustainable business for several reasons. For example, sourcing locally can help avoid long-distance shipping and help support a local economy (Vinish et al., 2021). Likewise, due to the Covid-19 pandemic, take-away channels and online food delivery (OFD) services via various platforms have become essential for both restaurant business operators and consumers. The competitive direction of the food delivery business remains highly regarded with the consumer trends where many actively use the service. The vast majority of players continue to provide discounts and promotions as an essential competitive tool. However, an accelerated expansion could push the market to get saturation status dramatically (Marketeer Magazine, 2020). Hence, encouraging customers who advocate the brand will be a potential marketing tool to sustain the brand's standing.
Building brand advocacy is one of the crucial goals of marketers for businesses to achieve sustainable success and improve an advantage over competitors. As the food markets evolved, consumer targeting transitioned from emphasizing demographics to a more sophisticated and efficient factor, withstanding that competition in consumer food markets is mainly about consumers' interests (Thomsen et al., 2014). The most significant way to surmount these challenges is to establish positive relationships with brands and customers by improving closer customer relationships (Firdaus & Kanyan, 2014). Several significant factors are related to the relationship marketing dimension, such as brand evangelism and brand advocacy (Wilk et al., 2020). In addition, the studies considered brand advocacy as part of relational behaviors, which refers to elective behaviors in which customers choose the activities for engagement (Bhati & Verma, 2020). Xiea et al. (2018) described three brand advocacy behaviors: positive word of mouth, negative information resistance, and intention to invest in the company. It can be noticed that three types of customer advocacy are the goal that businesses need. Thus, brand advocacy is valuable for marketers to create factors influencing brand choice and purchase decisions (Badrinarayanan & Laverie, 2011). However, creating customer advocates is similar to building brand loyalty in the long term (Schepers & Nijssen, 2018). Therefore, brand advocacy cannot be built with one specific variable in a short time.
This paper focused on studying the causal factor that can act as a guideline in developing customers' behavior into brand advocates in online food delivery services. Reviewing concepts and relevant research found that brand advocacy can be created by presenting customers' experience impressions and the quality relationship between a brand and the customers. Moreover, gaining brand leadership status also helps create sustainable brand advocacy. Therefore, the research result will act as a guideline for marketers in laying out their marketing strategies that meet customers' needs. Furthermore, every business can apply the results for future success in the business circle.

LITERATURE REVIEW AND HYPOTHESES
Through customer experience quality, this study found four definitions of customer experience quality. Meyer and Schwager (2007) identified customer experience as "customers' response to direct and indirect contact with a firm." Deshwal (2016) defined customer experience as the experience of receiving a service or a product, even after its delivery. Lemke et al. (2011) viewed product or service quality as a perceived judgment about excellence or superiority. Furthermore, Klaus (2015) conceptualized experience quality as the measurement of customers' evaluation of the experience of company quality that can be divided into three dimensions: brand experience, service experience, and post-purchase or consumption experience.
As mentioned above, it was found that the definitions by Meyer and Schwager (2007), Lemke et al. (2011), and Deshwal (2016) focused on the experience from business activities consisting of three views: service, product, and company.
However, Klaus (2015) improved the definition of customer experience quality to be broader and entirely in business view by adding the term brand, which is a critical tool of current business strategies. Thus, this paper defines customer experience quality as the perceived judgment resulting from evaluating experience from a brand, service, and consumption. Klaus (2015) conceptualized experience quality as measuring the customers' evaluation of the firms' experience quality, divided into three dimensions: brand experience, service experience, and post-purchase or consumption experience. Brand experience includes the perception of customers when dealing with a particular brand, influencing their experience and decision process. Service experience reveals three concepts associated with the experiences: the process experience, such as using multiple channels, the evaluations of interactions with company personnel, and the effect of the physical environment. In terms of post-purchase experience, it is the customers' experience after the purchase process, in other words, the consumption of the products. Furthermore, the term covers the perceptions of familiarity, retention, and emotion associated with the firms' value (Klaus et al., 2013;Klaus, 2015).
In the past decade, researchers have studied various views of customer experience, such as the relationship between customer experience and brand co-creation, retail experience, and transcendent customer experience (TCE) (Roy, 2018). Some research suggested that SERVQUAL can measure a perception from customers about the quality of experience and provide a multi-item scale for perceived quality measurement of service. Although SERVQUAL's dimensions are reliable and tangible, there were several limitations in measuring customers' experience. SERVQUAL focuses on assessing features of the service process, while customer experience relates to a perception of the customer consisting of five dimensions: rational, emotional, sensorial, physical, and spiritual (Klaus et al., 2013).
Thus, creating a solid customer experience is the fundamental goal of the management team at present (Lemon & Verhoef, 2016). As mentioned above, the current marketing trend is creating customer engagement and building long-lasting experiences to increase the proportion of gross domestic product to improve economic growth (Havíř, 2019). In addition, marketers emphasize customer experience quality and connect the more substantial customer relationship to complete the customers' value creation rather than focusing solely on the product and service quality. In other words, products or services from competitors in the same industry cannot easily compete with companies with good branding and strong leadership. Therefore, firms try to move forward sustainably by building a strong brand and efficiently leveraging available resources, including their leadership qualities (Ahmad et al., 2014). Thus, being a brand leader becomes an attractive strategy for those who want to grab a competitive advantage by expressing dominant social standing. Most studies state that promoting and developing brand leadership can be done by creating business-related innovations, increasing the volume of market share and international presence around the world, and providing various choices for consumers (Chiu & Cho, 2021). From another point of view, "brand leadership" typically refers to a brand's role and power as strategies to differentiate itself within the industry. Being a brand leader, one must be aware of the organizational efforts toward efficiency and sustainability. In other words, corporate leaders are well aware of the brand direction and are committed to brand performance (Ahmad et al., 2014).
brand image. The result helps a brand become more well-known and supports the company in maintaining its leadership position for a long time (Chang & Ko, 2014;Chang et al., 2016).
Generally, the company's overall profitability is evaluated based on relationship marketing activities. However, various variables concerning marketing activities also influence profitability for engaging relationships. Therefore, it is crucial to conceptualize relationship marketing outcomes appropriately when investigating possible antecedents (Thurau et al., 2002). In addition, building customer relationship commitment is a strategy for firms to retain loyal customers in this highly competitive environment (Su et al., 2016).
Relationship quality is widely conceptualized as vital in developing loyal customers and an essential predictor of customers' post-purchase behaviors (Su et al., 2016). Relationship quality is a construct consisting of various critical reflecting relationships between companies and customers. Previous research suggested the components or dimensions of relationship quality, such as cooperative norms, customer orientation, the expertise of the seller, and expectation to continue. Nevertheless, some research suggested that customer satisfaction, trust in the company, and commitment to the relationship between the company and customers are critical components of relationship quality. In previous research about relationship quality, the three core variables included satisfaction, trust, and commitment ( Finally, as a purpose of the study, brand advocacy is when customers with brand experience take the initiative to recommend a brand to others or support the brand's activities. Thus, the definition of brand advocacy is the effort of brand advocates to recommend and share their experience of using a specific brand with other relevant people (Badrinarayanan & Sierra, 2018). Brand advocates are loyal customers whose recommendations support a brand to generate new customers. Therefore, marketers' effort in building brand advocacy is the way to increase brand value (Bhati & Verma, 2020). Furthermore, other brand-advocating activities consist of brand recommendations to others, defending when a brand is under attack, or supporting every brand activity (Kemp et  The study aims to fulfill the marketing knowledge, especially branding. Thus, this empirical paper examines the correlation between customer experience quality as the primary antecedents of brand leadership, relationship quality, and brand advocacy of online food delivery services. The conceptual framework for the study is shown in Figure 1. According to the literature review, there is little empirical research on the relationship between customer experience quality and brand leadership. Lindgreen (2012) suggested that brand leadership combines essential dimensions, such as company reputation, firm performance, and the quality association between brand and customers. Moreover, this finding is consistent with Chang et al. (2016) and Henry and Greenhalgh (2005). They stated that firms provided superior operational processes quality or extraordinary experience for their brand to achieve the leading position in the marketplace. The finding of Mosley (2007) also revealed that customer brand experience helps a brand gain leadership in the service brand. Therefore, a brand experience quality should potentially affect brand leadership.
Likewise, previous studies found a positive relationship between customer experience on a particular brand and satisfaction and customers' loyalty (Brakus et  Based on these points, this empirical study examines the relationship between customer experience quality, brand leadership, relationship quality, and brand advocacy of online food delivery services. Thus, the study proposes these hypotheses: H1: Customer experience quality will have a positive relationship with brand leadership.
H2: Customer experience quality will have a positive relationship with relationship quality.
H3: Brand leadership will have a positive relationship with brand advocacy.
H4: Relationship quality will have a positive relationship with brand advocacy.

METHODOLOGY
The study sample was customers of food delivery platforms living in Bangkok and Metropolitan areas with the most population density in Thailand, consisting of Nakhon Pathom, Nonthaburi, Pathum Thani, Samut Prakan, and Samut Sakhon. In addition, these areas are also equipped with technological conveniences where most people live their lives through online services and is, therefore, a sample group that is particularly suitable for this analysis. This quantitative study used online questionnaires to collect data with judgment sampling. The data were  For the data collecting process, the survey link was sent to the respondents in July 2021. The respondents completed the questionnaire independently. The questionnaire was divided into five parts, 1) general information, including screening questions and demographic profile, 2) customer experience quality, 3) brand leadership, 4) relationship quality, and 5) brand advocacy. The measure used in the study was the questionnaire developed from reviews of the related literature. Customer experience quality was adapted from Klaus (2015) A 7-point Likert scale (1 = strongly disagree, 7 = strongly agree) was used for measurement due to its continuous data and to avoid the problem of normality. Harman's single-factor test was chosen to analyze the problem of common method bias. The exploratory factor analysis found that the variance of the first factor was 39.47 percent. It revealed no bias in the data (Podsakoff et al., 2003). Additionally, the skewness values of the data were between -0.547 and -0.747, and the kurtosis values were between -0.133 and 0.742. Both values were between -2 and 2, translating to a normal distribution (Tabachnick & Fidell, 2007). For the variance inflation factor, the values were between 2.730 and 6.734, and the values of tolerance were between 0.148 and 0.366. It can be seen that there was no problem with multicollinearity (Stevens, 2009). The data were then analyzed using Structural Equation Modeling via AMOS Graphic consisting of the measurement model and the structural model used as inferential statistics.

RESULTS
The sample of 562 customers using food delivery platforms, which included Grabfood, Food Panda, Lineman, Get, and Skoota in Bangkok and Metropolitan areas including Nakhon Pathom, Nonthaburi, Pathum Thani, Samut Prakan, and Samut Sakhon, Thailand, consisted of female (73.3%) and male (26.3%). All of them (100%) had used food delivery service from the food-tech platforms as mentioned above. The mean values of questionnaire items were between 4.75 and 5.76, and the standard deviation values were between 1.027 and 1.639. Correlation matrix results were between 0.171 and 0.760. The discriminant validity was assessed. Table 1 shows that the square root (AVE) value of each construct was greater than its correlation value, which demonstrates the discriminant validity of all constructs (Hair et al., 2010).

Measurement model analysis
The results of confirmatory factor analysis (CFA) of customer experience quality consisted of three factors: brand experience (three items), service experience (five items), and post-purchase experience (four items). Brand leadership consisted of four factors: perceived quality (two items), perceived innovativeness (three items), perceived value (two items), and perceived popularity (two items). Relationship quality included three factors: trust (four items), satisfaction (three items), and commitment (two items). Lastly, brand advocacy consisted of three factors: recommendation (four items), purchase intention (two items), and brand defending (two items  (Hair et al., 2010). Therefore, the results provided validity and reliability of measurement (Table A1).

Structural model analysis
In terms of the investigation of the relationship between customer experience quality, brand leadership, relationship quality, and brand advocacy, the results of structural equation modeling analysis revealed coherence with empirical data, with Chi-Square/df = 1.920, GFI = 0.900, CFI = 0.972, RMSEA = 0.040, and SRMR = 0.034 (Byrne, 2010;Kline, 2010), as seen in Figure 2.

Figure 2. SEM result of building brand advocacy in online food delivery
The results of the model revealed that customer experience quality had a positive relationship with brand leadership (β = .97; P < .001) and relationship quality (β = .94; P < .001), which alternately positively predicted brand advocacy. As expected, indirect effects of customer experience quality on brand advocacy were indeed mediated by brand leadership (β = .21; P < .05) and relationship quality (β = .66; P < .001). Thus, all hypotheses were supported and showed a 72% relationship with brand advocacy.

DISCUSSION
The hypothesis testing revealed that all hypotheses are accepted: customer experience quality (brand experience, service experience, post-purchase experience) positively affects brand advocacy (recommendation, purchase intention, and brand defending) through brand leadership (perceived quality, perceived innovativeness, perceived value, and perceived popularity) and relationship quality (trust, satisfaction, and commitment).
The empirical result found that the crucial variables that are the antecedent factors in creating brand advocacy consist of three components of customer experience quality, especially the service experience dimension, which is the most essential. This factor aligns with the context of the food delivery service business, which focuses on customer service as the main factor for both online and offline platforms. The second component is the post-purchase experience. The research result showed that customers like that brands care about the post-purchase service while constantly presenting new information to customers, such as updating new menus, presenting promotions for regular customers, and the component of brand experience. In addition, customers like the presentation of superior and higher quality experiences from a brand, such as quality offerings of brands and the services by staff who excellently convey a brand. Hence, a brand that provides quality customer experience, service process, and post-purchase service can become one of the leaders in the marketplace. This result is consistent with Henry and Greenhalgh (2005) In the context of online food delivery service, customers who receive quality experiences will have positive brand awareness, especially the awareness of outstanding superior innovations, since online food delivery service platforms are a type of service that aims at technological development, presentations of creative experience, and products on the platform. With the above mentioned, a brand will gain leadership status in customers' hearts and lead to brand advocacy. The statement is in line with Hanaysha (2016) and Bhati and Verma (2020), who stated that perceived brand leadership is an essential factor affecting brand advocacy, mainly through word of mouth about the content, especially by opinion leaders, and other positive advocacy behaviors.
According to the results, another influential factor affecting brand advocacy is creating customer experience quality through the quality of the relationship between brands and customers, especially in customers' satisfaction and trust. The results showed that presenting a quality experience to customers, as well as building satisfaction and trust, can increase the level of customers' advocacy. Customers who are satisfied and happy with using a brand through the online food delivery service, as well as the feeling that a brand is trying to respond to their needs actively, such as insurance or compensation for customers in the case of damages that happened with customers, will help them to pass on this impression with a high possibility of using the service again in the future. This is in line with Becerra and Badrinarayanan (2013) and Bhati and Verma (2020), who stated that people who become brand advocates are also likely to pass along trustworthy information about a brand. Finally, when brands are trusted, customers are likely to engage in risky and difficult situations to support a brand, such as making purchases and using the product, positive brand word of mouth, and brand defending. In addition, customers who get high satisfaction and commitment are likely to act as product or brand advocates. Thus, it can be concluded that recommendation and brand defending are advocacy characteristics that increase as satisfaction increases.
Regarding the online food delivery service context, more supportive customers with recommendation behavior or purchase intention can be created by delivering a superior customer experience. To create a superior customer experience, firms must consider three aspects: brand experience, service or provider experience, and post-purchase experience. The first initiation should be paying attention to staff quality, such as standard uniforms and other brand elements, to create awareness of good brand quality management. Moreover, services and facilities of both online and offline platforms are crucial factors in becoming a superior brand. Firms must consider every touchpoint as part of the best and most convenient service process and facilities to respond to customers' needs. Finally, a brand needs to continuously provide a high-quality service experience even after the purchase process, such as providing a channel to receive customer suggestions, assurance, and guarantees to resolve possible mistakes in the products and those caused by the staff. These quality experiences can lead firms to be the leading brand and stay top regarding customers' choices. Eventually, they would become advocacy customers providing only positive information about a brand, repeat purchases, and defending a brand from negative comments and feedback. Building brand advocacy can also be achieved by creating a quality relationship between customers and a brand. Besides providing a quality customer experience, firms need to build customers' trust toward a brand, such as satisfaction guarantee, increasing satisfaction in every process, and always maintaining brand commitment. Eventually, customers who gain more satisfaction would likely be loyal and protect a brand in adverse situations.
In brief, business organizations, especially those related to food products and online food delivery services, can apply the research result as a marketing strategy to develop online marketing suitable to the current competitive business context. Likewise, the results can be applied to create an online and offline quality experience for target customers to gain an impressive experience with a brand. These strategies can make a brand outstanding and become an accomplished leader in the industry, resulting in a good relationship between a brand and consumers, who, as a result, will spread positive stories and support various brand activities, creating sustainable competitive advantages.

CONCLUSION
The empirical study aims to investigate the antecedents of brand advocacy in the online food delivery service. These factors include customer experience quality, brand leadership, and relationship quality. The results recommend that brands should highlight the importance of providing an impressive experience and transform customers into advocates through being brand leaders and establishing a superior relationship quality with their customers. The current model contributes to a better understanding of how to fulfill today's gap in marketing strategies for online platforms. As the world is faced with the crisis of the Covid-19 pandemic, all businesses have to adopt different strategies to combat this critical situation. Businesses related to fundamental human needs are crucial in helping society survive this challenging situation. Consequently, food services still have to improve their production, transportation, and marketing processes requiring various competition strategies from other key players to combat this epidemic. Thus, the findings can contribute to both practitioners and academics.
For further research, it is advised to conduct a comparative investigative research of the different variables to build brand leadership, relationship quality, and brand advocacy, especially in an online context, which is the most effective tool to build customer advocacy and brand reputation. For example, in an online context, companies build online communities for their brands with the beneficial functions of online platforms. Communities allow brands to share their interactions with potential customers, build brand awareness, and influence their purchase decisions by providing customers with information about brand quality, where quality perception is an essential component of brand leadership. Thus, a brand with good leadership maintains corporate values, supports and empowers people, drives the community, and provides valuable knowledge for customers.