Official IAB definition:
"An ad impression takes place when a user requests ad content from a publisher or ad-server. This request should meet conditions for measurement specified in the IAB Guidelines for Ad Impressions, although the responsibility for ad-impression measurement does not necessarily reside with or is under the control of the same organization measuring the click activity."
Highly Recommended for All Web Publishers:
Are you a publisher or advertiser looking for the right internet advertising network? Check out our overviews of interactive marketing providers, including online ad networks such as Tribal Fusion, ValueClick, Adconion, Casale Media, and dozens more. We cover display advertising networks, text-based advertising, contextual ads, viral, pre-roll video, mobile, in-image advertising, performance networks, and everything else in the internet advertising realm. Click here for the complete list of internet advertising networks.
Reviews of selected top internet advertising networks:
