This chapter focuses on how existing scholarship on popular music fandom can contribute to emerging discussions of media streaming platforms. It examines how platforms reformat traditional fan practices and how fan patterns and behaviors are incorporated into the very workings of streaming media services. The chapter argues that future work at the intersection of fan studies and popular music studies needs to consider platforms as both objects of fandom and the means through which fandom is organized and commodified. Studies of fandom in the field of popular music studies emerged in reaction to mass cultural critiques that focused more on the regressive effects of industrialized, rationalized, and standardized music production than on the pleasures of fandom. The chapter explores how the platform acts as a technology for formatting fandom that re-directs traditional popular music fandom by incorporating ever greater amounts of fan activity into the workings of the platform.