Prior research on information technology (IT) adoption has examined adoption of individual technologies with little attention to the adoption of IT platforms. IT platforms are general purpose technologies that are used by application developers to build specific applications for individual or organizational needs. IT platform adoption is different from the adoption of independent IT, in that (1) platform adoption requires substantial up-front knowledge investments, (2) the potential benefits from such adoption depend on network externalities, and (3) adopters are developers rather than end-users. To understand what factors drive IT platform adoption, we interviewed 35 developers of mobile applications and analyzed their responses using a grounded theoretic approach. Our findings suggests that a wide range of factors drive IT platform adoption, including platform characteristics, network externalities, personal motivation, personal knowledge and innovativeness, and social influence.