From Credibility to Advocacy: An <scp>SOR</scp> Model of Consumer Engagement and Authenticity in Functional Foods and Beverages Market

ABSTRACT This study examines how influencer marketing stimuli; perceived source credibility (PSC) and perceived content–persona fit (PCPF) at the organism level affect engagement consistency (ECS), interactive influence value (IIV), and content authenticity index (CAI), and how these further affect the consumer advocacy propensity (CAP) in the functional food and beverage industry. According to the Stimulus–Organism–Response (SOR) paradigm, the paper postulates advocacy as a consequence of response to communication based on credibility and fit. A survey of 250 Indian consumers with pre‐use experience of functional foods and beverages was undertaken. Interestingly, PCPF had a larger indirect effect on CAP than did PSC, and this underscores content–persona alignment in crafting advocacy. The research underscores the need to choose influencers whose persona and content match brand values and consumer aspirations. For functional foods and beverages marketers, establishing authenticity and engagement through authentic influencer collaborations has the ability to shift consumer attitudes into advocacy, a compelling type of organic word‐of‐mouth (WOM) promotion. This research contributes to consumer behavior theory by proposing CAP as the response construct in the SOR model for the functional foods and beverage market. It broadens advocacy research to the functional nutrition field, with empirical evidence of how influencer marketing manifests as consumer‐driven brand advocacy.