By using multilevel mediation involving 322,589 posts made by 384 musicians over 104 weeks, we simultaneously analyze the short-term and long-term effects of charity-related signaling on sales, with social media engagement as the mediator. Specifically, we compare the effects of charity-related signals with those of two other types of signals: mission-related (i.e., promoting music and commercial products) and non-mission-related (i.e., other posts that do not relate to the other two categories). In the short term, the indirect effect of using charity signaling on sales (through engagement) is positive, though smaller than the effects of mission-related and non-mission related signals. However, in the long term, the indirect effect of regularly using charity-related signaling on sales (through long-term engagement) is greater than for the effects involving the other types of signals. We derive from these findings three main implications for the business ethics literature. First, in the long term, the mutual economic benefits of charity signaling should encourage both entities (i.e., musicians and charities) to go beyond short-term, transactional philanthropy. Second, because it is profitable for musicians to partner with charities in the long-term, our research argues that charities have extensive bargaining power in such co-branding decisions. Third, our research highlights the importance of studying the longitudinal aspects of co-branding decisions involving non-profit organizations; the financial outlook of such decisions could greatly vary depending on the timeframe (i.e., short vs. long).