There is growing evidence that online peer reviews posted on online-to-offline (O2O) commerce platforms are a valuable source of information stimuli in consumer purchase decision-making. The research into the impact of different factors related to environmental stimuli (online peer reviews) on consumers’ continued log-in behavior is under-researched in the context of O2O meal delivery apps (MDAs). Drawing on the theoretical lens of stimulus-organism-response and pleasure-arousal-dominance (PAD) models, this study examined the role of text and pictographic online review content in evoking emotions that predict continued log-in behavior on MDAs. Using a quasi-experimental setup with 134 participants from Germany, the findings reveal that the textual content of reviews positively related to pleasure and arousal, whereas the pictographic content of reviews generated pleasure and arousal. All three emotions of PAD were found to be significant predictors of the MDAs continued log-in behavior. In addition to the main effects, the results also showed the mediating effect of pleasure and arousal on continued log-in behavior. Moreover, app familiarity was found to moderate the effect of review content on emotions, implying that consumers with high app familiarity evoke fewer diners’ emotions than those with low app familiarity. In the unique Western cultural context of this MDAs setting, the findings have important theoretical and practical implications for academicians, MDAs managers and developers, and food delivery firms.