Recent studies have shown that using social media is a new way of promoting user participation and understanding potential user needs for a service firm. However, user participation via social media might produce synergistic and interactive effects, including issues of social interaction with members and technical interaction with social media. The purpose of this study is to examine the impact of user participation via social media on continuance intention and customer engagement behavior from a sociotechnical theory perspective. In total, 381 respondents were selected in the context of the social network brand community. The hypothesized associations were examined by using partial least squares-structured equation modeling. This study found that interaction with social members (social issues) mediates the association from social media (technical issues) to continuance intention. Additionally, continuance intention is positively associated with customer engagement behavior. These findings not only complement the theoretical arguments of sociotechnical theory but also enrich the understanding of the existing literature on relational marketing.