Extending the effectiveness of media-based campaigns into interpersonal networks has been a long concern for studies on persuasive messages, yet there is much to understand about why people attempt to persuade others to engage in health-related behaviors. This study investigated two alternative predictors of interpersonal persuasion: psychosocial determinants of behavior and homophily. We used the integrated model of behavior (IMB) to predict consumers' intentions to purchase antibiotic-free meat, and extended the model to predict consumers' intentions to encourage important others to do so. IMB variables predicted 44% of future purchasing intentions and 40% of future persuasion intentions. The findings support a homophily explanation for persuasion: people intend to persuade important others to do what they do. In addition, a person-centered analysis identified three audience segments based on antibiotic-resistance-related behaviors, cognitions, and experiences: Purchasers, Resisters, and New Adopters. The covariate analysis revealed that people who had more topic awareness of antibiotic use in animal husbandry, knowledge of someone with an antibiotic-resistant infection, and health mavenism were more likely to be Purchasers than Resisters or New Adopters. Anxiety, however, was highest among New Adopters and lowest among Resisters. Implications for theory and practice are discussed.