Nearly a quarter of digital advert impressions are faked, according to a new study. This advertising fraud is set to cost the industry $6.3 billion in the next year, reports Channel Eye.

The study, by White Ops and the Association of National Advertisers studied the behavior of bots that mimic human movements to generate clicks and watches.

The advertising fraud works by drawing away money from brands by setting up fake websites or driving fake customers to websites that use third party traffic. In one instance, Reuters reports, an unnamed premium lifestyle site had 98% of its video ad views faked by bots.

The Guardian reports that the survey was quite far reaching, encompassing 181 online campaigns from 36 companies including Nestle, Kellogg's and Anheuser-Busch, the brewer of Budweiser. Around 5.5 billion ad impressions were observed over two months, and fraud was apparent everywhere - including major websites.

Video ads were the hardest hit, with bots accounting for between 0.3 and 63 percent of views - for a weighted total of 23 percent of video impressions. Display advertisements fared better, with an average of 11 percent artificial views, based off a range of 0.8 to 32 percent.

Other interesting stats revealed that monetized audiences were supposedly inflated between 5 and 50%, Internet Explorer 6 was 58% bot traffic and that the peak time for bot activity was between midnight and 7am - when human traffic would be expected to be markedly lower.

Bob Liodice, president and chief executive of the Association of National Advertisers, welcomed the report saying, "We have long suspected and have long known there was fraud in our industry. We didn't know the exact amount or the reasons why it was happening."

"We have been less than fully active largely because we didn't understand the problem and because we were enamored by the success of digital to the marketing industry. We want to ensure that everyone has accountability," he added.