Corporations use social media to build online communities, in order to create and maintain product loyalty and source new product ideas. Community members discuss the corporation's products, services, or practices. Topics range from suggestions for products, enhancements, or services. Users communicate their grievances to each other and the company, hoping to garner support and change. Posted messages contain not only the substance of their claims, but also cognitive and affective influence tactics. How do these embedded influence tactics mitigate the efficacy of claims in persuading others to support the burgeoning movement? Results provide partial support for the model developed, indicating that (1) efficacy of claims on community comments was negatively moderated by negative affect and assertiveness; (2) efficacy of claims on points awarded by community members was positively moderated by rational persuasion; (3) efficacy of claims on comments by corporate employees was positively moderated by rational persuasion.