Customers’ post-adoption switching behavior among competing service providers, particularly among different online Social Network Sites (SNSs), is gaining increasing attention from both information system researchers and practitioners, as the size of user base is both a selling point and a source of revenue of SNS service providers. In this study, we draw on the uses and gratification theory to identify factors motivating an individual to switch SNSs. In addition, informed by social identity theory, we explore how individuals’ social identities on their current SNSs moderate the effects of the motivating factors on their intention to switch to a more attractive SNS. The results of our survey study reveal that the perceived relative values of a competing SNS (when compared with the user’s current SNS) positively influence his/her intention to switch to the competing SNS. However, the positive impact of perceived relative values on switching intention is mitigated by the user’s perception of his/her salient social identity on his/her current SNS. This study has significant implications for both academics and practitioners.