Why do citizens get politically informed in a democracy? On one hand, being informed allows a citizen to participate in political discussions within her social network. On the other hand, having an informed opinion can help her to extend her social network. This paper builds a simple model on these insights and finds that effort in political information acquisition has inverted-U shape in the size of social network. The data from the 2000 American National Election Study and the 2002–2006 European Social Surveys confirm this theory: political information acquisition, political knowledge, and interest in politics increase with the size of social network, at a decreasing rate. The effect of social network is much weaker for the political efficacy measures for the United States, but not for Europe.