Political parties play a crucial role in linking citizens’ preferences and political decision making. As one way to address linkage problems and to enhance policy representation, only recently political parties tend to encourage participation via the Internet between elections, e.g. by online platforms which allow citizens and party members to discuss policy issues and generate proposals. However, in most cases only few people take part. Drawing on the case of the German Green Party and applying three well established models that explain political participation offline, the paper tries to explain why some party members use these innovative channels to communicate their preferences while others do not. Comparing users and non-users, we conclude that neither socio-economic resources nor attitudes alone can explain participation. Rather, participation is motivated by an efficient and credible involvement of the participants of online platforms in concrete policy processes.
