In this discussion paper we outline two approaches to the use of social media for public sector innovation. The two approaches are described as two roles that can be assigned to social media. The co-creation role concerns the use of social media for collaborative contributions to research and development, exemplified by public sector idea portals. The network role concerns the use of social media for sharing, dialogue and access to expertise, exemplified by the appropriation of general purpose social network applications to the networking needs of professional groups. Our distinction between these two roles for social media is a useful contribution as it facilitates a nuanced discussion of how social media should be employed in public
sector innovation and may serve as a basis for future research.