Increasing the attractiveness of voting is often seen as a remedy for unequal participation and the influence of special-interest groups on public policy. However, lower voting costs may also bring less informed citizens to the poll inviting efforts to sway these voters. We substantiate this argument in a probabilistic voting model with campaign contributions. In an empirical analysis for the 26 Swiss states, we find that lower voting costs due to postal voting are related to higher turnout, lower average education of participants, lower knowledge on the political issues they were deciding on as well as lower government welfare expenditures.