Impression Fraud is a fraudulent practice by which ads are delivered and counted as served without having any chance to be seen by users.
The most common types of impression fraud are:
- invisible ads displayed in hidden IFrames
- impressions generated by botnet traffic
- bots hosted by the fraudsters and mimicking human visits
- Ad Stacking – stacking several banners on top of each other, serving and charging for all of them, while only one of them can effectively be seen
Impression Fraud is especially met on some ad exchanges and ad networks. Although it is difficult to evaluate, some studies estimate that up to a third of all ad impressions are fraudulent.
Since it has become a serious threat to the online and mobile advertising business, several solutions have been developed for companies to detect Impresion Fraud and protect from it. Advertisers can e.g. hire fraud detection companies, use accredited ad servers or use viewability solutions that try to make sales in mobile advertising more transparent.