Campaign ads and the differences between soliciting donations and mobilizing volunteers

Research on political participation has long emphasized differences between Americans who donate money to political campaigns and Americans who perform other kinds of political activity. It's unclear, however, if there are distinctions in how campaigns use advertisements to solicit donations and mobilize grassroots voters. Analyzing Facebook ad data from thousands of ads, donations, and e-mail sign-ups from a recent statewide gubernatorial campaign, we show that campaigns deploy ad themes that vary in their success at attracting donations and mobilizing grassroots activists. Ad effectiveness varies by region of the state as well. Ideological extremity boosts small donations and campaign sign-ups. However, less ideological campaign messages are also effective, perhaps because recipient lists are already curated to include the candidate's likely supporters.