Research on student-run communication agencies (SRAs) documents significant learning outcomes, benefits for job placement, and career success. Research, however, rarely investigates cultural aspects of the agency experience. This study employed in-depth interviews with agency student leaders and advisors to explore the influence of agency culture on positive student experiences and agency success. Informants described the importance of collaborative and supportive cultures in achieving agency goals and the role of agency-based friendships in creating positive student experiences and increased student retention. Yet they also noted agencies attracted a relatively homogenous group of students and, consequently, acknowledged the need for increased diversity, equity, and inclusion (DEI) initiatives.