This study explores how complementors in platform ecosystems adapt their strategies in response to platform-owner entry, focusing on how these responses depend on complementors’ pre-existing integrative strategy. Taking the entry of Apple Fitness+ as an empirical setting, we investigate how developers of fitness and health applications adjust their innovation and integration efforts when facing direct competition from the platform owner. Leveraging a difference-in- differences (DiD) approach, our analysis reveals that complementors with pre-existing integrative strategies reduce innovation efforts in directly affected areas while reallocating resources to enhance integration across treated applications. This strategic adaptation helps mitigate competitive risks by leveraging complementarities within the broader platform ecosystem. The findings highlight significant heterogeneity in complementor responses, emphasizing the role of integrative strategies as a counterbalancing force to platform-owner dominance.
