The affordance of social interaction has been a part of open online repositories of teaching and learning resources for nearly two decades. Repositories are built not only to collect and disseminate materials, but enable users to collaborate and review, comment on and rate the content they access. However, research indicates that (a) most users do not participate in this type of generative use, and (b) the possibility of social interaction does not necessarily signal active participation in social interaction. In recent years the positive effects of gamification and social networking elements on user engagement have come to the fore in educational settings. From this stance, a quantitative study was conducted to assess users' acceptance of the existing game mechanics of a large national repository of educational resources, their attitudes towards the inclusion of extra features, and teachers' motivation to share openly. Our results indicate that teachers do not see open repositories as social networks, but as libraries of resources, and are likely to share if rewarded by intrinsic rather than extrinsic factors.