Abstract

Purpose: By combining entertainment, user-generated content (UGC), and e-commerce features, digital platforms—particularly TikTok—are changing how consumers behave and interact with marketing messages. TikTok has developed into a powerful communication tool in Vietnam, where customers are beginning to trust key opinion consumers (KOCs) more when making decisions about what to buy. User-generated content produced by key opinion consumers (UGC by KOCs), has the power to impact consumer behavior through emotional appeal, informativeness, entertainment value, and educational value. This is due to its emotional qualities, personal experience, and high recommendability. This study uses the Elaboration Likelihood Model (ELM) to investigate how social and content factors—such as online opinion leadership and parasocial interaction—affect users' intentions to share and shop on TikTok. Research design, data and methodology: A structured questionnaire was used to gather data from 568 TikTok users in Ho Chi Minh City, and the PLS-SEM method was used for analysis. Results: The findings demonstrated that while viewer arousal was significantly influenced by content factors, viewer arousal only had an effect on sharing intention; purchase intention was not significantly impacted. In the meantime, both intentions benefited from social factors. Conclusions: The study helps to expand the ELM model for short videos and offers useful advice for companies looking to maximize user-generated content on TikTok in order to enhance marketing efficacy and establish brands.