Increasing number of firms are adopting enterprise social media (ESMs) for their day-to-day communication. Despite the spending made on these IT tools, participation levels on ESM are not high. Under this background, it would prove to be helpful to understand the impact of basic features on ESM affect usage. Thus, we investigate the role of social groups on participation levels in workgroups on ESMs. Social groups can be considered a psychologically safe environment, where users are allowed to make mistakes and take risks. In addition, casual conversations within social groups make it easier for users to start conversations with other employees that they do not know. The study results provide guidelines to companies and developers on how to use and design social features in an environment where personal and professional lines would become blurred. To empirically test this, we relied on the usage data of users from thousands of companies. A difference-in-difference estimation approach was used to contrast users who participate in social groups to those who do not. We used the matching methods to alleviate endogeneity concerns and constructed various control groups to difference out the selection effects in the DID technique. To conclude, we found evidence of a positive impact of social groups on user participation in workgroups on ESMs. The comfort levels and shared experience gained from social groups spilled over to the workgroups, particularly for lower-ranked employees as uncertainty and concerns of being criticized are reduced. Study implications are discussed.