Social networking platforms such as Facebook and Instagram allow political actors to target users with digital political advertisements based on the algorithmic analysis of vast user data. This chapter provides the first analysis of how parties from all 27 EU member states used digital political advertising during the 2024 European Parliament election campaign, and how this strategy developed compared to the 2019 EP election campaign. We analyse the volume of, spending on, and the reach of political ads placed by parties from all EU member states (N = 272) on Facebook and Instagram in the 8 weeks leading up to the EP elections in 2019 and 2024. Our findings reveal significant cross-country differences, with varying implementation strategies regarding the volume and spending on political ads. We show that parties from different member states reach uneven numbers of people for the same amount of money, and that higher spending on ads does not necessarily guarantee higher visibility. Since the 2019 EP elections, the use of digital political advertising has intensified in most countries; however, distinct strategic adaptations regarding volume and spending, as well as differing developments in the cost-efficiency in audience reach are observed. The uncovered differences in the use and reach of digital political advertising contribute to the ongoing debate around unfair electoral competition when using social media platforms’ algorithmic advertising tools in democratic elections.