We propose that attributions about an endorser truly liking, using, or desiring a promoted product mediate the relationship between source and message factors and persuasion via endorsement. In this paper, we integrate the persuasion literature into a framework for examining endorser effectiveness via focus factors (e.g., involvement, cognitive load) that determine whether a consumer thinks carefully or superficially about a message, and lead consumers to rely on different source and message elements (e.g., source attractiveness, argument strength). These elements then influence attributional processing. Correspondent inferences about an endorser can lead to enhanced advertisement and brand attitudes, and spur either fleeting identification with the endorsement or more enduring internalization (Kelman, The Public Opinion Quarterly 25:57–78, 1961) of the endorser’s message as a consumer’s own. Implications of our framework and research directions are discussed.