The widespread application of Web-based technology has contributed not only to the content of advertising but also to the improvement of presentation formats. Animation has become a powerful presentation format on the Web. Despite its potential benefits, however, animation is no panacea. Practitioners and academics have been paying increased attention to the exploration of effective advertising strategies in the e-commerce environment. Drawing on theories in cognitive psychology, this study, by using a laboratory experiment, investigates the roles of presentation formats, content relevance and shopping tasks on ad recognition. The results show that abrupt and looming formats are effective formats in improving ad recognition. There is a significant three-way interaction between the formats, content relevance and shopping tasks on ad recognition. Specifically, the interaction effect of animation formats and content relevance is observed in browsing tasks, but not in searching tasks.