Heightened interactivity and excitement characterize much of our online browsing, especially when it involves shopping on e-commerce websites. Interactivity is said to affect users’ engagement with the website by expanding their perceptual bandwidth (Sundar, 2007), much like the effect of optimal physiological arousal on cognitive functioning (Kahneman, 1973). We examine the direct and combinatory effects of interactivity and arousal on consumers’ engagement, attitudes, and behavioral intentions in an e-commerce website through a 3 (interactivity: low, medium, high) x 3 (arousal: control, low, high) between-participants experiment (N = 186). Higher levels of interactivity were found to generate more favorable attitudes and behavioral intentions toward both the website and the product. Interactivity and arousal differed in their effects on various aspects of website engagement. The study also identified several mediators explicating the theoretical mechanism underlying the influence of interactivity on purchase likelihood.