Main Article Content
The value of Thai e-commerce grew to 14% in 2018, reaching $102.13 million, and the growth is expected to continue to show a 20% increase, which indicates that Thailand has become one of the most important countries in ASEAN e-commerce according to the Electronic Transactions Development Agency (ETDA). Meanwhile, competition among e-retailers has also become increasingly fierce. This study aims to investigate the ‘what’ and ‘how’ of factors influencing the Thai customers’ buying behavior through pre- purchase, purchase, and post-purchase phases. An expanded research model based upon the theory of planned behavior was employed. The research used survey questionnaires to collect data from a sample of 535 online consumers to test the hypotheses and adopted a structural equation modeling to analyze data. The results show that the basis of the theory of planned behavior (i.e., attitude, subjective norms, and perceived behavior control) positively impact the consumers’ behavior. Marketing channels and Marketing strategies directly affect the consumers’ purchase intentions; and the compatibility of payment method, delivery, and aftersales services significantly impacts post-purchase behavior and consumer purchase intention. It is hoped that this study results will serve as a useful reference for e-retailers seeking to gain a better understanding of online customers’ buying behavior through multiple-stage perspectives.