This study empirically analyzed customer journey based on data surveyed on 217 users of Toss and Kakao, the leading domestic fintech services in South Korea. Since the customer journey in the digital environment is different from the customer decision model of the past, the customer journey was confirmed by using the 5A model of Kotler et al (2017). By redefining the steps of the 5A model to match the purpose of this study and validating the path with the structural equation model(SEM), the result has shown to follow the steps of Aware-Appeal-Ask-Advocate. In particular, since the key success factor of a platform business is the network effect, and the sense of belonging among users of SNS services has an important effect, it was assumed that the question confirming the sense of belonging due to the use of the service at the Ask stage will strengthen the Advocate. As a result of verifying this by hierarchical regression analysis, it was confirmed that there was a completely mediating effect of the question stage. These results have implications in terms of customer acquisition and management strategies in a situation where competition is overheated due to market entry by non-financial companies.