Abstract: The platform literature has shown conflicting findings regarding how a platform owner's entry into its complementors' market affects complementors’ innovation. To reconcile these mixed findings, we present a dynamic perspective on platform evolution within and across technology generations. We argue that in the early stage of a platform's technology generation, the platform owner’s entry provides vicarious learning opportunities for complementors to understand and reduce their technology and demand uncertainties, thus encouraging their innovation. However, in the late stage, the platform owner's entry increases competitive pressure on complementors, thus discouraging their innovation. We further explore how technology gaps between two successive generations and complementors' product portfolios’ attributes moderate these relationships. Our findings, using data from the game console industry (2000–2020), strongly support these arguments.