Cause-Marketing (CM) has gained momentum in recent years, both in marketing research and practice. However, while CM aims to influence consumers on an emotional or affective level, research into the emotional and affective response to CM campaigns is scarce. The current research fills this void by showing that a CM campaign is a win win win strategy. Though the tangible benefits of CM campaigns go to the firm and the philanthropic cause, our perspective is novel by arguing that the consumer benefits as well, albeit intangibly; CM campaigns provide an opportunity to do good, and hence induce feelings of gratitude in consumers. However, this effect depends on several contingencies. In particular, consumers perceive greater effort by small firms, relative to large firms, that engage in CM campaigns, leading them to assess the underlying motives as more sincere and then experience stronger feelings of gratitude for the opportunity to donate. Four experiments confirm this greater CM effectiveness for small compared with large firms. In turn, this study offers substantive contributions for both marketing research and practice: It proposes a cost-effective strategy for enhancing CM effectiveness, and specifies concrete strategies for both small and large companies. (C) 2018 New York University. Published by Elsevier Inc. All rights reserved.