The Impact of Crowd Interaction in Live Streaming Commerce on Gen Z's Impulse Buying Behavior: An S-O-R Framework Approach

Live streaming commerce has emerged as a dominant retail channel in Vietnam, significantly altering consumer purchasing dynamics through real-time social engagement and high-interactivity environments. Drawing upon the Stimulus-Organism-Response (S-O-R) framework, Social Influence Theory, and the Fear of Missing Out (FOMO) perspective, this study investigates the empirical mechanism through which crowd interactions in live streaming streams influence the impulse buying behavior of Generation Z consumers. A quantitative cross-sectional design was executed, sampling 297 validated Gen Z respondents across major shopping platforms including TikTok Shop, Shopee Live, and Facebook Live. Structural Equation Modeling via Partial Least Squares (PLS-SEM) was utilized to evaluate measurement scale validity and test structural path hypotheses. The empirical findings reveal that Viewer-to-Viewer Interaction (β = 0.203, p < 0.05), Streamer-to-Viewer Interaction (β = 0.437, p < 0.001), and Perceived Product Popularity (β = 0.223, p < 0.001) significantly and positively stimulate Herd Psychology among Gen Z live streaming audiences. Subsequently, Herd Psychology exerts a profound positive influence on Impulse Buying Behavior (β = 0.630, p < 0.001), explaining 39.5% of the variance in unplanned purchasing decisions. Mediation analysis confirms that Herd Psychology functions as a robust complementary mediator bridging environmental live interactions and spontaneous purchases. Strategic managerial implications for e-commerce merchants and digital broadcasting platforms are discussed, alongside structural limitations and future empirical trajectories.