Previous studies in the context of livestreaming commerce have largely overlooked the role of the distinctive characteristic of real-time interactivity in fostering cognitive/affective reactions and subsequently impulsive buying. Drawing on the stimulus–organism–response paradigm, this study contributes by investigating the link between real-time interactivity (responsiveness and personalization) as stimulus and impulsive buying as response with causal association between inspiration (inspired-by and inspired-to) and delight as organism under the moderating effect of idea shopping motivation in the context of livestreaming commerce. A conditional model linking interactivity and urge to buy impulsively is proposed and tested using the partial least squares structural equation model (PLS-SEM) technique with SmartPLS software on a sample of 376 livestreaming commerce viewers. The findings indicate that inspiration experience and delight are causally associated as the bridge connecting real-time interactivity and urge to buy impulsively, and idea shopping enhances the link between real-time interactivity (responsiveness and personalization) and inspiration (inspired-by). Based on the findings, some important theoretical and practical implications are proposed.