My colleagues at the University of Western Ontario recently did an extensive study of user generated content. "The goal of the Mobilizing User-Generated Content for Canada’s Digital Content Advantage project is to define User-Generated Content (UGC) in its current state, identify successful models built for UGC, and anticipate barriers and policy infrastructure needed to sustain a model to leverage the further development of UGC to Canada's advantage." Trosow, S. E., Burkell, J., Dyer-Witheford, N., et al. (2010). Mobilizing User-Generated Content for Canada’s Digital Advantage. London: Faculty of Information and Media Studies, University of Western Ontario. http://ir.lib.uwo.ca/fimspub/21/