In this article, I analyse the Steam platform as a configuration of several market contexts. I argue that Valve, the owner of Steam, maintains a classical retail market catering to large game publishers, while the emphasis of Valve’s own game titles is in alternative market contexts based on player-driven economies. I first discuss Steam as a distinct type of platform economy due to its roots in player-driven game economies. I then introduce the notion of ‘markets as fields’ as my analytical framework. Based on this framework, I describe three different contexts of economic transaction: the Steam Game Store, the Steam Community Workshop and the Steam Community Market. I analyse how the approximately 46,500 game titles published on the platform are distributed across these contexts and how these games can be ranked with regard to current player numbers, and discuss Valve’s position as combined platform owner, game developer and game publisher.