Vote-buying has and continues to be pervasive in many electoral regimes. Yet the relationship between vote-buying and citizen behavior, particularly in the context of the secret ballot, remains largely unknown. In this paper I study vote-buying’s effect on voter turnout in Kenya, using a nationally representative survey that includes questions about the country’s 2002 presidential and parliamentary elections. Estimating the causal effect of vote-buying on voter turnout is complicated by the strategic nature of vote-buying, and so this study also examines the strategic logic of vote-buying in Kenya. The results suggest that poor individuals and “swing” voters in the country’s most electorally competitive districts are most likely to be targeted by vote-buyers. Using these results, I use probit statistical models as well as propensity score matching and estimate that individuals who were approached by a vote-buyer were about 14 percentage points more likely to vote than those who were not, while the least educated individuals were the most highly influenced by vote-buying. These results are puzzling. If voting is secret and voluntary, why does vote-buying have an impact on individual behavior? I propose and test the empirical implications of two potential explanations: a monitoring and punishment mechanism, and a credibility signaling mechanism. The evidence is tentatively consistent with the monitoring and punishment mechanism, and is also consistent with the credibility signaling mechanism. I conclude with discussion of the study’s implications for theories of vote-buying and for the quality of democracy and political accountability in settings where vote-buying is commonplace.