For nearly a decade, social media have gradually taken a predominant place in various organizations. Their contributions and potential are now recognized worldwide. In turn, libraries have seized these media to promote their library holdings, maintain a link with their users, create online communities and involve users in their processes of innovation. The instantaneous and interactive nature of these media seems to favor exchanges between librarians and users and encourage the generation of new ideas. This is part of a reasoning of open and participatory innovation. We note a paradigm shift in the profession of librarians through the changes imposed by the digital. This evolution makes us consider the innovation of services in a horizontal and interactive way with and by users. The idea that innovation comes only from internal library is now abandoned. The purpose of this paper is to show how the presence of academic libraries on social media promotes the emergence of innovative services. Two surveys were conducted both involving librarians and 137 users of several French universities. Three primary results emerged from this analysis from the professionals’ and the users’ point of view. After a state of the art on innovation in libraries through social media and a presentation of the methodology, the authors present the main results. Social media favor the emergence of new services and convey the image of a library that is an open environment and encourages participative and open innovation. These results can be compared to similar work internationally.