Electronic marketplaces have been struggling to find business models able to both (1) attract a high number of clients thereby enabling them to exceed their critical size and (2) create sufficient value to guarantee their viability and the satisfaction of their users. There operators are still hesitating between two strategies: the ‘cost out’ which is mainly based on the functionalities of the e-sourcing and e-procurement, and the ‘value in’ which requires a more collaborative form of relation between the members of these marketplaces, especially buyers and suppliers. In this article, we propose to study the communities using free software and adapt their key success factors to the marketplaces in order to design a new economic model based on collaborative commerce. The study of the Qt community and its influence on the excellent results of the company Trolltech will service as a basis for this study.