1. Introduction
Facts indicate that there is promising potential for the mobile application industry, whose total generated value is forecasted to reach more than USD 613 billion in 2025. The consumption volume in the number of apps downloaded has witnessed a soar of 80% to 255 billion in 2023, only after seven years [
1]. Nowadays, an average individual spends over three hours daily on smartphone activities [
2,
3]. Hence, doing business based on mobile applications has become an inevitable trend.
Vietnam, whose population is up to 100 million [
4] and whose volume of apps downloaded ranked in the top 10 worldwide in 2021–2022 [
5], is a potential market for developing app-based businesses food delivery applications, which is a relatively young but fast-growing industry in Vietnam. In 2022, this segment together with shared transport service was estimated to surge by more than 60% in 2025 [
6]. Specifically, the sole segment of food delivery applications is currently assessed to be worth USD 1.1 billion, served by some prominent brands like Grab, ShopeeFood, and Baemin [
7].
The mechanism of FDA operations in Vietnam consists of the participation of five parties, including:
- (1)
Food order fulfilment platforms such as Grab, Baemin, and ShopeeFood;
- (2)
Crowd shippers who register with the platform to physically pick up the food from stores and deliver it to customers;
- (3)
Restaurants that are registered as partners with the platform;
- (4)
Customers who browse the app to look for food, place an order, and pay for the meal, delivery service, and order processing service;
- (5)
Supporting service providers (e.g., payment service).
Several studies have evaluated the influencing factors to identify triggers for and barriers to the behaviour of customers using FDAs [
8,
9,
10]. There are a number of theories applied to establish research models to explain consumer behaviour towards FDAs including the TAM and DOI [
11], TPB [
12], UTAUT [
10], expectancy confirmation model [
8], and perceived risk theory [
13]. The results from these studies contribute to the identification of key determinants that govern customer behaviour in many markets. Most of the studies focused on application-centric factors, evaluating the overall performance of applications, whereas FDAs in Vietnam adopt a sharing economy model involving five categories of participants. This leads to a concern whether factors contributed by other stakeholders have any effects or not. Therefore, elements related to food retailers, service providers, and customers as well as their impacts should be further explored. So far, there have been a number of studies in the field of FDAs. Specifically, Zhao & Bacao [
8] evaluated factors having an impact on customer satisfaction and intention to continue usage in China by applying the UTAUT and expectancy confirmation model, but their study did not cover attitude variables and did not focus on Gen Z users. Other studies analysed the upsides that technological features of FDAs have without investigating the influence of personal variables on customer behaviour [
14,
15]. Some studies were carried out during the COVID-19 pandemic [
8,
10,
15]; therefore, it is necessary for an empirical study on the behaviours of FDA users in the post-pandemic context. Although some studies mentioned the importance of money-related benefits like promotion, cost savings, and price value [
9,
15,
16], factors that have an impact on how FDA users perceive those monetary advantages have not been researched in depth. Furthermore, it is still recommended that the commonly applied TPB be expanded and empirically assessed in various contexts to obtain a higher explanation level [
17,
18,
19,
20], and studies applying these models in Vietnam are still limited.
Another point that should be highlighted is that the mentioned studies did not precisely target Gen Z users, who account for one-third of the world’s population and will be the leading consumers in the future [
21]. The Gen Z group accounts for one-quarter of the Vietnamese labour force, equivalent to approximately 16 million people who are forecasted to become key consumers [
22]. Gen Z customers are individuals who are proactive in using technology in life, have highly personal innovativeness, and have careful consideration when making consumption decisions [
23,
24]. Furthermore, many characteristics of Gen Z customers are also found to bring challenges for businesses, such as low loyalty and frequent impulse buying behaviours [
24,
25]. In particular, the psychology and behaviour of individuals may have a great change after a long time of being negatively affected by the COVID-19 epidemic [
26].
From what has been discussed, a study to extend theories and investigate the influences on continuance usage adoption, specifically for the Gen Z segment, is necessary. This study is expected to fill the previously mentioned gaps with four objectives:
- -
Establish a conceptual model to explain Gen Z customers using FDAs.
- -
Validate the measurement scale and model and assess the impact of several factors on the continuance usage intention of Gen Z customers using FDAs.
- -
Propose theoretical and practical implications to stakeholders to help develop the sustainability FDAs market.
5. Discussion, Implication, and Conclusions
5.1. Discussion
This study is one of the first to apply the TPB to assess the FDA usage behaviour of Gen Z customers in Vietnam—a potential market for FDA service, according to our best knowledge. By conceptualizing and validating the measurement scale and structural model, this study helps enrich knowledge about innovation technology adoption of Gen Z customers in an emerging economy. This study is a response to calls from some academics to expand and refine the TPB in technology adoption studies, especially in need of increased empirical research on adoption in different contexts [
17]. This study reconfirmed the suitability of the TPB to explain individuals’ technology adoption similar to other previous studies [
53,
56]. The results demonstrated that applying the TPB could effectively explain Gen Z customers using FDAs. Compared with some similar studies on FDAs, the explanation level of the TPB model in this study is higher [
37,
40,
59].
In this study, the SEM analysis highlights the significant role of attitude in continuance usage intention. This finding is the same as the observation by famous scholars [
28,
35]. The attitude–behaviour gap does not exist, and it implies Gen Z customers are more inclined to continue using FDAs when they have a good attitude towards FDAs. In addition to attitude, subjective norm—one basic component of the TPB model—also has a direct impact on continuance usage intention. This result reflects the role of a high level of collectivist culture in individuals’ decision-making [
54].
This study found perceived usefulness of promotion could dramatically enhance the continuance usage intention of Gen Z customers using FDAs. This result is similar to the views of some similar studies in Southeast Asian markets such as Indonesia and Malaysia [
9,
59]. This finding is partly explained by the financial limitations of Gen Z customers, as illustrated in the sample characteristics: most respondents have moderate and low monthly incomes. Thus, financial benefits from promotions showed the ability to significantly improve the continuance usage intention of Gen Z customers.
This study extends the TPB model by adding perceived health risks that effectively explain the perceived usefulness of promotion and continuance usage intention of Gen Z customers. This finding reinforces other views that perceived health risk is related to the decisions considered in several previous studies conducted in other markets, such as Australia [
63]. However, this finding is contrasted in comparison with other studies conducted during the COVID-19 period [
38,
64]. The differences can be explained partly because FDA services seem to be an obligate option in the COVID-19 context. The results of the SEM analysis emphasized the essential role of promotion in improving the adoption of customer FDAs, which is similar opinions of other research [
9,
59]. Interestingly, this study recognised perceived health risk as a new factor that can decrease the perceived usefulness of promotion, which implies that health benefits should be considered carefully along with price benefits.
Finally, this study highlights the critical role of personal innovativeness in attitude. This finding is similar to conclusions from previous studies [
40,
42,
54]. FDAs with many valuable functions allow customers to save time, recommend many useful options, and create many experiences with outstanding features. Hence, this service easily attracts young customers who are highly innovative.
5.2. Contribution and Implication
5.2.1. Theoretical Contribution and Implication
Firstly, this study suggested and validated measurement scales with high reliability regarding FDA adoption in emerging market contexts by extending the TPB model. These findings helped enrich knowledge about innovation technology adoption by Gen Z customers in Vietnam and carried out a new approach to establish conceptual models. This study also reconfirmed previous observations of other previous studies about FDAs as well as technology adoption [
9,
38,
64]. In particular, this study found a negative effect of perceived health risk on the perceived usefulness of promotion. This finding extends knowledge about customer behaviour using FDAs because most previous studies focus on the essential role of promotion in FDA adoption [
9,
59] instead of exploring new factors to explain the usefulness of promotion. Thus, these findings suggest theoretical implications that researchers should extend theories such as TPB to explain individuals’ behaviour and re-examine the relationships between factors in various contexts. Furthermore, the validated models and measurement scales could become the essential background for future research about relevant themes.
5.2.2. Managerial Contribution and Implication
This study helps identify the key determinants that influence Gen Z customers using FDAs. Therefore, enterprises, technology providers, and policymakers can understand insights into the consumption habits of Gen Z customers, thereby being able to devise appropriate business strategies for this customer segment.
Firstly, this study indicated that the perceived usefulness of promotion is a key determinant influencing continuance usage intention. Thus, enterprises should focus on improving the effectiveness of promotions by providing suitable discounts and terms for Gen Z customers. However, these promotions should ensure other conditions, such as the minimum price of orders to receive promotions and the expiry date.
Secondly, several practical implications are for FDA enterprises to reduce perceived health risks, which significantly decrease the usefulness of promotion and continuance usage intention of Gen Z customers. Enterprises need to complete policies to ensure food hygiene and safety for restaurants registered for business on applications. In addition to supervising activities, enterprises can strengthen the development of interactive channels to receive customer feedback on food safety and hygiene issues. Finally, research indicates that Gen Z customers pay attention to health benefits. Thus, FDAs could develop more communication channels about nutrition and healthy lifestyles to orient customers’ consumption habits in addition to normal advertising activities.
Thirdly, the role of subjective norms should be strengthened as this factor significantly boosts the continuance usage intention of Gen Z customers. Enterprises can establish and develop customer groups to create opportunities for customers to communicate, exchange information, and share user experiences and feedback after using FDAs. Notably, this study implies that innovative customers are a potential segment market, so FDA enterprises and technology providers can consider adding new innovative technology features to enhance Gen Z customers’ experience, such as applying artificial intelligence, biometrics, and big data technologies. These technologies can aim to make applications more thoughtful and practical, such as suggesting more valuable choices, enhancing information security, and improving users’ health through the knowledge and experience provided by FDAs or other users.
Finally, this study emphasized that attitude is a critical factor affecting the continuance usage intention of Gen Z customers. Thus, enhancing attitude is a possible approach to attract customers using FDA services. This finding suggests that enterprises should promote compatibility and relative advantage aspects of system quality. Furthermore, delivery time, packaging, and shipper interactions should be ameliorated to enhance attitude.
5.3. Conclusion and Limitation
The sharing economy business models applying innovation technologies in FDAs, ride-hailing, and hospitality with prominent big brands such as Uber, Grab, and Airbnb are gradually gaining popularity and attracting the participation of stakeholders as both suppliers and customers. Applying the TPB, this study evaluated the influence of several factors on the attitude and continuance usage intention of Gen Z customers in Vietnam—a typical emerging economy in Southeast Asia.
This study proposed and validated a conceptual model using CB-the SEM method to fulfil three objectives. These findings help identify the key determinants affecting the attitude and continuance usage intention of Gen Z customers using FDAs. Based on the results, several implications are also suggested to stakeholders to improve business performance. In addition to reaffirming some of the promoting and inhibiting roles of some factors on the behaviour of customers using FDAs, this study also found that the characteristics of Gen Z customers partly explain these differences compared with previous studies. The research findings have also shown that, in order to promote the behaviour of using the FDA platform, enterprises need to evaluate the comprehensive influences of various factors, the quality of personal factors, and the quality of business characteristics, including customers. The goal is to bring maximum benefit to customers. This study also enriches knowledge about customer behaviour research and contributes to theoretical and practical aspects.
Several limitations are still recognized in our study, such as the small sample size and many demographic characteristics, such as monthly income, shopping frequency, age, and gender, that could not be analysed for influence on the behaviour of Gen Z customers. Finally, the conceptual model is still basic, and some important factors for explaining the operational capabilities of the application, the role of the shippers, and trust of restaurants on the application have not yet been included in the assessment. Hence, the conceptual model should be extended to improve the explanation level for dependent factors.