Agreements and charters for Europe’s public service broadcasters increasingly include ambitions for developing partnerships and engaging in collaboration. The recent management contract of VRT in Flanders specifically includes a new strategic objective to implement partnerships in order to strengthen the wider media ecosystem, including cross-sectoral media partnerships and co-operation with private media companies. This chapter clarifies relevant concepts and offers a framework for the development of partnership strategy that premised on a belief that public service media should be a central node in a networked media system. Research on ecosystems in business literature structures our framework and offers metrics for evaluating media ecosystem health and sustainability. The metrics are illustrated through an empirical analysis of the media ecosystem in Flanders. Risks and benefits of public service media partnerships are assessed. The practical framework specifies criteria for selecting, assessing and managing partnership proposals and serve as building blocks for public service media organisations to make ex ante estimates about which partnerships will be most beneficial for public media in the light of its public service mission.