While word-of-mouth (WOM) activities may be planned by marketers, customers have to execute them. And although marketers may attempt to encourage customers to do so by providing either unconditional or conditional incentives, customers have the ultimate control whether or not they execute WOM-related activities. WOM senders' actions might be somewhat aligned with a company's objectives, but marketers have even less control over the responses of WOM receivers. Thus, from the receivers' perspective, this paper examines how incentivized WOM should be designed to boost the success of a marketing program. The theory of planned behavior serves as a framework to explain both the internal and the external drivers that determine receivers' reactions to WOM stimuli. An experimental design is applied to investigate different modes of mobile coupons as a novel tool of WOM. Gender is identified as a major source of heterogeneity in receivers' responses. Results show that incentives' conditionality exerts a negative impact on receivers' responses. The inequality of incentives does significant harm to WOM campaigns that are aimed at male consumers. By contrast, external drivers exert a particularly strong influence on females' reaction to WOM stimuli. Situations of reciprocity reduce women's perceived behavioral control and thereby increase their likelihood to execute the desired WOM action. Research findings hint at the need to design gender-specific incentive schemes to foster WOM.