This study examines the paradoxical relationship between prosocial content on social media and the self-promotional nature of many social media platforms. Specifically, our study examines how differences in two perceived affordances—persistence and visibility—affect how women viewers evaluate the authenticity of men who post allyship messages on Instagram. Additionally, we examine how viewer perceptions of comment deletion and comment restriction impact source evaluations. Results indicate that greater perceived persistence and visibility led women viewers to rate ostensible allies as more authentic and less self-interested. Moreover, comment deletion and restriction were found to partially affect how viewers evaluated ally authenticity and motive, providing additional support to warranting theory. Implications for promoting prosocial messaging and digital allyship online are discussed.