The research presented in this manuscript examines how social sponsorship can be made more commercially effective. To this end, the effects of two leveraging factors are explored by means of an experiment: the extent to which the social sponsorship is seen by consumers as legitimate, and that to which the sponsor is perceived as sincere. The results show that these two factors have a positive and statistically significant impact on consumers’ intentions to purchase the sponsor’s products. In addition, they show that the sponsor’s perceived sincerity increases when the sponsorship is combined with philanthropic investments, either in sequence (i.e. philanthropy followed by sponsorship) or simultaneously, and that the legitimacy of a sponsorship is enhanced when the cause and its sponsor are congruent. These results are discussed in the context of the literature on social sponsorship, and managerial implications for firms that contemplate using social sponsorship as a marketing communication strategy are derived.