Sectors from hospitality, consumer finance, freelance services to taxis have been reshaped in the last few years due to the growth of online access-based sharing platforms. Notable examples of such platforms are Airbnb (accommodation services), Lyft (mobility), TaskRabbit (freelancing), and Kickstarter (peer lending). The chapter posits that access-based sharing platforms are subject to an evolution from “peer-to-peer” (P2P) to “integrated” forms, where the platform owner adopts a series of governance mechanisms aimed at providing effective safeguarding, adaptation, and measurement features to transactions. The level of transaction frequency, uncertainty, and specificity is a strategic decision taken by the owner to grow the platform. The management of transaction features generates transaction costs and determines the need, by the platform members and by the platform owner, to adopt specific mechanisms of platform integration. The chapter concludes with a call for scholars to intensify empirical evaluation of the important and growing phenomena identified in the chapter.