This article provides a novel answer to explain the persistence of party rallies in the mass and social media era. I argue that rallies contribute to the organizational structure of clientelistic parties by providing information to different members within and outside the machine. Rallies provide party leaders with information that enables them to monitor brokers’ capacity to mobilize voters, party brokers with an opportunity to display their ability to turn out voters while monitoring voters’ responses, and voters with an opportunity to display their gratitude or fear towards brokers. In addition, rallies provide the opposition with an opportunity to gather information about the electoral strength or weakness of the clientelistic party. Drawing on participant observations, over a 100 interviews, archival research in Argentina and Peru, and secondary literature for the cases of Mexico and Brazil, I explain why political parties conduct rallies and why rallies will continue in the future.