Viewable Impression

• abstract: In the online advertising industry, a Viewable Impression is a metric of ads which were actually viewable when served (in part, entirely or based on other conditional parameters). The first system to deliver reports based on a Viewable Impression metric for standard IAB (Interactive Advertising Bureau) Display ad units,called RealVu, was developed by Rich Media Worldwide and accredited by the Media Rating Council on March 9, 2010.

以上来源于: WordNet