The rise of social networks has revolutionised political communication, providing parties with powerful tools to target and engage voters with precision. This study explores how political parties adjust their advertising strategies based on electoral outcomes and regional characteristics. It specifically investigates the role of regional factors—such as district magnitude and party system fragmentation—in shaping these strategies. Using the Meta Ad Targeting Dataset, we analyse a sample of approximately 15,000 ads to understand how Spanish political parties tailor their messaging geographically. By integrating targeting data with regional political and historical factors, the study uncovers the strategic motivations behind digital political advertising. Our results demonstrate that the Effective Number of Electoral Parties (ENEP) is a significant predictor of targeting strategies in a region. In fragmented political systems like Spain, this suggests that parties adapt their messages to appeal to niche audiences, where vote margins are narrower and mobilisation becomes more critical. We also find that, on average, Spanish statewide parties focus their advertising efforts on smaller districts (excluding Podemos). Additionally, parties that were close to securing the last seat in a region tend to intensify their efforts in the following election, aiming to surpass this threshold. These findings contribute to the growing field of online political communication, offering new insights into how parties navigate the evolving digital and electoral landscape. The study highlights the interplay between regional dynamics and the influence of social media platforms in shaping political messaging, shedding light on how electoral strategies evolve within multilevel governance contexts.