Persuasive messages often have deep implications that conflict with their superficial meaning. As a result, they can be interpreted in multiple ways, which may help explain striking real-world successes and failures of persuasion. We analyze theoretically and experimentally how the interpretative process controls the effects messages have on preferences. In our model, attributes and the relationships between them are mentally organized in a causal schema described by a Bayesian network. Due to this structured mental representation, seemingly negative information can be viewed in a positive light, or vice versa. When intended, these alternative interpretations may support clever advertisements; when unintended, they might cause campaigns to backfire. We conduct an experiment based on the car rental agency Avis and their famous slogan, “We're No. 2–that means we try harder,” and show that their ad's effectiveness can be predictably modulated by altering background beliefs. Thus a richer depiction of mental structure can shed light on the economic impact of persuasive messages.