eParticipation has largely not lived up to expectations and government responsiveness to public feedback, provided via eParticipation has proved challenging. In a new conceptualization of the theory of Sense of Community (SoC), this paper explores the dynamics of online government responsiveness, using dimensions of SoC to identify how those components enable successful interaction from both the perspective of government staff and public users. This study reports from two case studies designed to explore these interaction dynamics in online engagement initiatives in Ireland and the UK. The findings enabled the identification of important factors which facilitate successful SoC (for online public interaction) in this domain. Participation for government staff users was particularly associated with their perception of a safe online space. For public users, openness without responsiveness to public feedback was not valued, highlighting the importance of appropriate government responsiveness. The absence of social interactivity was identified as a negative for public users while the presence of social interactivity was identified as a positive for government staff users in the second case study. Overall, this study is the first empirical step to contribute to an understanding of successful social online processes in online public engagement. It highlights the utility of examining all four subconstructs of SoC and proposes factors to assist in the identification of critical SoC components in future studies.