Tailored Messages in the Feed? Political Microtargeting on Facebook during the 2019 General Elections in Spain

The Facebook advertising platform provides a tool to target messages at specific profiles and to display them on those users' feeds. Political parties benefit from this marketing instrument as it allows them to target online voters with specific contents in a highly personalized strategy. This research analyses a dataset of 14,677 ads downloaded from the Facebook Ad Library and sponsored by the five main Spanish parties during the two General Election campaigns in 2019. Political microtargeting strategies have been explored and our findings suggest that old and new parties alike used this platform, apart from Vox. The other parties implemented different strategies, with PSOE making a more intensive use of this and Podemos the least. Contrary to our expectations, age-based targeting was the least prevalent criterion. Sex and geography were the main variables for targeting according to our data. Finally, the most microtargeted topics followed a similar pattern to the parties' ideological position. One of the more controversial issue in the campaign was the country's cohesion, and Ciudadanos and PP addressed this with an outstanding level of microtargeting.