This paper is an executive summary of the Online Advertising Effectiveness Study which the Internet Advertising Bureau commissioned MBinteractive to conduct. The study was designed to help value the advertising impact of online communications since much of what is known and predicted about the medium is within the context of direct marketing. The study was conducted in a real world setting with real brands on real media sites with the real audience of consumers naturally accessing the Web sites so that the most representative results could be provided and focused on the effects of advertising banners. Online advertising using banners has tremendous communications power. In fact banners can impact the traditional marketing measures of advertisement awareness brand awareness brand perceptions and potential for sales all from one exposure.