Purpose As customers increasingly adopt social media as the primary channel to reach out to companies, voicing is becoming a public act. Adopting a social psychological perspective, this study aims to focus on the social dynamics that drive consumer voice on social media. Design/methodology/approach The research uses three studies. First, a list of metaperceptions about voicing behavior is compiled using the critical incident technique, and then the hypothesized effects are tested with two scenario-based experiments. Findings Metaperceptions mediate the relationship between social anxiety and the intention to voice on social media. Self-construal moderates the effect of metaperceptions, such that in the presence of a negative metaperception, the reluctance to post a direct complaint is attenuated under independent self-construal. Independent self-construal attenuates the positive effect of positive metaperception. An experimental comparison between social media and consumer review sites reveals that metaperceptions are only prevalent in social media and when the complainer construes him or herself as interdependent. Originality/value Since lodging a direct complaint to a service provider has been mainly conceived as a private behavior, the role of social dynamics in the context of voicing remains under-researched. Aiming to fill this gap, the present research empirically examines how the presence of a perceived audience affects voicing behavior.