T He F Ormation of S

Thanks to Web 2.0, retail websites and online communities provide user reviews to help consumers make purchase decisions. Current IS and marketing literature reveal that user reviews can form strong social influence on consumers’ purchase decisions. However, few studies systematically examined how social influence is developed from user reviews. To bridge the gap, our research explores what factors impact the formation of social influence from user reviews. Based on a survey conducted in a controlled lab environment, the results suggest that review quality positively impacts informational influence while review consistency negatively impacts informational influence. Review consistency and social presence positively impact value-expressive influence. We also incorporate product expertise and self-monitoring as moderators into the model. Interestingly, product expertise weakens the relationship between social presence and informational influence. Self-monitoring does not impact value-expressive influence in online settings. Managerial implications are discussed.