This article discusses the ways in which the relations among professional and non-professional participants in co-creative relations are being reconfigured as part of the shift from a closed industrial paradigm of expertise towards open and distributed expertise networks. This article draws on ethnographic consultancy research undertaken throughout 2007 with Auran Games, a Brisbane, Australia-based games developer, to explore the co-creative relationships between professional developers and gamers. This research followed and informed Auran's online community management and social networking strategies for Fury ( http://unleashthefury.com ), a massively multiplayer online game released in October 2007. This paper argues that these co-creative forms of expertise involve coordinating expertise through social-network markets.