User-Generated Content and Viral Marketing Effects on Purchase Intention: The Moderating Role of Product Knowledge among Gen Z

In the digital era, social media marketing plays a vital role in shaping consumer behavior, especially among Generation Z, known for high digital literacy and content-driven preferences. This study examines the impact of user-generated content and viral marketing on the purchase intention of the local beauty brand Emina, with product knowledge as a moderating factor. Using an associative, quantitative approach, data were collected from 175 Gen Z consumers in Medan through purposive sampling. Respondents were aged 15–24, active on social media, and past Emina product users. Structural Equation Modeling (SEM) analysis revealed that both user-generated content and viral marketing significantly enhance purchase intention. Additionally, product knowledge positively moderates these effects on purchase intention.