Type of the article: Research Article Abstract The research on influencer marketing often treats social influence as a monolithic concept, overlooking the distinct persuasion mechanisms that underlie it. This study addresses that gap by disentangling social influence into two pathways: informational and normative, within the context of Vietnam, an emerging market with a characteristic collectivist culture. A theoretical model is proposed wherein influencer trustworthiness and expertise affect purchase intention through these pathways, moderated by argument quality. The study is based on survey data from 301 followers of social media influencers in Ho Chi Minh City. This sample was purposefully selected, as young, predominantly university-educated individuals are the primary consumers of influencer content and drivers of influencer-led marketing activities, making their responses a relevant lens for understanding persuasion dynamics in this demographic. Acknowledging its specific scope, the findings are not for direct global generalization but offer contextualized insights into a non-Western market, providing a valuable counterpoint to existing literature. The results show that both informational and normative influences positively affect purchase intention, with trustworthiness being a stronger predictor than expertise. The study’s most unique contribution is revealing the asymmetric moderating role of argument quality: it significantly strengthens the relationship between normative social influence and purchase intention. Still, it does not affect the informational influence path. This discovery suggests that in a collectivist context, a logical argument’s power is amplified when it aligns with the consumer’s desire for social conformity. This distinction advances persuasion theory by clarifying how source credibility and message content interplay differently across social influence mechanisms.
Tran et al. (2025) studied this question.