This study examines the relationships among customer attribution of success, emotional responses, and behavior in purchase success situations, seeking to explore the customer attribution process following success. Prior studies have suggested that when customers succeed in a purchase, they experience positive emotions that in turn elicit positive behaviors—meaning that customer success triggers positive customer responses, which leads to corporate success. However, the positive emotions experienced by customers who succeed in a purchase do not always have a positive impact on customers' behavioral responses. Upon success, customers undergo an attribution process, and depending on what they attribute the success to, they may experience different emotions. Even though these emotions are positive, they exert different effects on customer behavior. In other words, they may elicit behaviors favorable to the firm, but they may also elicit behaviors that are not favorable. Therefore, this study raises the question of whether "the customer's (your) joy can become the firm's (my) joy" and, through this inquiry, seeks to find answers regarding customers who do not engage in behaviors favorable to the firm despite their success. This study proposes ability, effort, and salesperson assistance as customer attributions upon purchase success, and feelings of competence, relief, and gratitude as the emotional responses resulting from these attributions. The results showed that in purchase success situations, ability attribution elicited feelings of competence, effort attribution elicited relief, and salesperson assistance attribution elicited gratitude. Feelings of competence were found to have a negative effect on revisit intention and no significant effect on word-of-mouth intention. Relief was found to have a positive effect on revisit intention but no significant effect on word-of-mouth intention. Gratitude was found to have a positive effect on both revisit intention and word-of-mouth intention, providing an opportunity to reaffirm the importance of gratitude. These results reveal that although an emotion may be positive from the customer's perspective, it may not be positive from the firm's perspective. That is, not all positive emotions experienced by customers who succeed in a purchase elicit positive behaviors; rather, the positive emotions experienced through the attribution process of success may or may not elicit positive behaviors from the firm's perspective. This provides an opportunity to reconsider customers' positive emotions, and in particular, offers an opportunity for an in-depth examination of the characteristics of positive emotions based on the causes of success and the resulting behavioral dimensions.