This article aims to identify some of the socio-economic implications of elevating users to the rank of designers. Undertaking a socio-economic analysis of user innovation means starting with user-innovators' initiatives, and examining their ramifications in the community and the market. It also means taking into consideration the permeability of boundaries between firms and co-designer communities, and being the witness of the construction of a twofold offer: a community offer, and a market offer. Finally, it also means looking at the benefits of community externalities in the realization of a market project and, vice-versa, the benefits of market externalities in the implementation of a community project.