An increase of the innovation contests and their associated prizes have been observed since the 90s especially in the US through the sponsorship of the American Federal Agencies. The purpose of this article is to shed light on some of the direct and indirect effects of US federal agency contests not only on economic dynamics but also on social dynamics. Based on recent case studies, this paper describes the various positive impacts that federal agency contests may have: i) contests may display a strong incentive effect ex-ante and during the contest; ii) they may produce favorable spillovers after the contests, at innovation and economic levels in specified economic/industry sectors and iii) they may also play a beneficial social role, contributing to citizens' education and awareness. Nevertheless, as a contest remains a sophisticated device, public decision makers must comply with certain requirements if they wish to benefit from this particular policy tool in order to spur innovation.