There has been an increase of funding agencies' investment in informal science education in recent years, resulting in significant growth of the field. However, little research has been done in discipline-based education research to determine the impact of informal physics programs and what makes them successful. While structures exist to assess the impact of informal learning, those are not yet robust enough to rigorously assess which programs work and, more critically, why they work. In this study, we used a non-profit organization framework as a lens to evaluate the 'success' of three informal physics programs in achieving their objectives and overall vision. To determine the practices and structures that most influence the 'success' of these programs, we conducted interviews with directors and coordinators of the programs, hosted at R1 institutions and identified initial indicators that can increase chances of informal physics programs to be 'successful'.