Digital VideoAd Serving Template (VAST) is a technique to measure the advertising efficiency of web videos.
The technique is used by the online advertising industry to evaluate the page impress ions or ad impressions within an Internet video. VAST was published by the Internet Advertising Bureau (IAB) and can be downloaded as a white paper from their website.
Digital Video Ad Serving Template describes a document that is embedded as an advertising medium in front of or within a web video. The clicks on such an XML document are evaluated by the ad server.