Digital platforms increasingly influence most online markets and ecosystems, creating substantial value for their customers, owners, and other partners. Yet, the challenges associated with platform operations, governance, and regulation continue to evolve. This paper aims to help researchers understand the extensive platform literature to facilitate effective academic contributions. First, we lay out emerging research topics and open questions related to platforms, both from an internal (platform design) and external (platform regulation) perspective. Then, we compare techniques for acquiring and using platform data, both with and without the collaboration of the platforms themselves, to facilitate empirical platform research. Our insights highlight the importance of multidisciplinary and multi-method approaches in studying digital platform policies, value chains and regulation.