This study examined the influences of positive brand-related user-generated content (UGC)1 shared via Facebook on consumer response. The model tested was derived from the S–O–R consumer response model (Mehrabian & Russell, 1974) that depicts the effects of environmental/informational stimuli on consumer response. Specific research objectives were to investigate whether brand-related UGC acts as a stimulus to activate consumer behavior in relation to brand and examine the processes by which brand-related UGC influences consumer behavior. Using the S–O–R model, brand-related UGC was treated as stimulus, pleasure and arousal as emotional responses, and perceived information quality as cognitive response. Information pass-along, impulse buying, future-purchase intention, and brand engagement were treated as behavioral responses. Participants (n = 533) resided in the U.S. and had a Facebook account. Mock Facebook fan pages including brand-related UGC were developed as visual stimuli and presented via an online self-administered questionnaire. SEM was used to analyze the data. Brand-related UGC activated consumers' emotional and cognitive responses. Emotional and cognitive responses significantly influenced behavioral responses. Positive brand-related UGC exerts a significant influence on brand as it provokes consumers’ eWOM behavior, brand engagement, and potential brand sales. •A model examining the influence of brand-related UGC on consumer was proposed.•The process by which brand-related UGC influences consumer was examined.•Brand-related UGC activated pleasure as emotional response.•Brand-related UGC influenced perceived information quality as cognitive response.•Brand-related UGC influences eWOM, brand engagement, and potential brand sales.