Platform competition literature emphasizes the importance of network size on platform value; however, as platforms expand in scale, the challenge of diminishing network effects emerges. Recognizing this, the role of user engagement as a critical driver for sustained platform success has garnered heightened attention. We investigate how platform-specific content, tailored to the unique features of the platform, influence user engagement. Focusing on Twitter’s character limit increase, designed to enhance platform-specific content creation, we investigate its impact on user engagement. Employing a synthetic control method and difference-in-difference estimation, our findings reveal that the character limit increase promotes platform-specific content creation by specific users (such as journalists). We suggest that crafting platform-specific content fuels user engagement (e.g., likes, replies, and retweets) on the platform. Importantly, we demonstrate that this impact is more pronounced for users with extensive networks and those generating creative content. We conclude with both theoretical and practical implications for platform ecosystems.