Social media enables public sector organizations to connect with citizens. Next to this, it can help organizations provide more detailed and useful information. But to what extent is social media used by local governments for interaction purposes, and what factors influence this? In this article, we study how Dutch local governments use Twitter for interaction, linking this to political, institutional, and socio-economic determinants. We find that politically fragmented municipalities use Twitter more for interaction, suggesting that political multiplicity forms a stimulus for more online engagement. Moreover, municipalities that have a Twitter account for a longer time make more advanced use of its functions, implying that municipalities with longer experience are better acquainted with a platform's strengths and weaknesses. Finally, municipalities with a higher presence of people in the age group 20–65 as well as municipalities with more higher-educated people use their social media more for interaction. The same counts for municipalities with more ICT workers.