This article is concerned with the interdependencies between public service broadcasters and the third sector, an area in which there is little research that has provided in-depth analysis of case studies. It investigates and compares three public service broadcasting (PSB)-Friends groups in the UK, Australia, and South Africa. By means of analyzing semi-structured interviews and archival data, we address development, institutionalization and policy impact of the Voice of the Listener & Viewer, ABC-Friends, and SOS Coalition. Drawing on resourcemobilization theory we argue that, in particular, material, human, and informational resources, contextualized with political opportunities, have analytic value in explaining similarities and differences between the groups, which are conceived as a microcosm of public interest media advocacy.