Banner ads function as both image and direct response advertising. Industry wisdom assumes that banner ad characteristics affect the viewer's recall and clicks; however, most evidence is anecdotal. This study examines the viewer's cognitive response as a function of banner ad size and type in a lab experiment. The study finds that animated banner ads result in quicker response and better recall than non-animated banner ads and that large banner ads lead to better comprehension and more clicks than small banner ads. User mode—information-seeking or Web-surfing—was not found to affect the viewer's response to banner ads.