Online retail platforms face significant challenges, including intense competition, the chicken-or-egg dilemma in acquiring consumers and sellers for network effects and establishing sustainable growth models. This article addresses these challenges by focusing on the concept of generativity: a platform’s ability to expand product and ecosystem boundaries, thereby unlocking the potential economies of scale and scope. Drawing on experiences from both small and large online retail platforms, we outline an extended set of strategic actions to foster generativity by engaging consumers (e.g., facilitating consumer creativity), complementors (e.g., creating open marketplaces), and their cross-sided interactions (e.g., extending interaction along consumer journeys). For each strategy, we provide practical, actionable recommendations that platform owners can implement to expand their product offerings and add new functions and services to improve interactions between participants. By emphasizing the importance of integrating the contributions of both consumers and complementors, these strategies foster a dynamic and innovative platform ecosystem, which is crucial for the sustained growth and competitiveness of online retailers.