The results seem staggering: Advertisers are essentially throwing half of their budgets away every time they pay for display ads. Some 56.1% of all the impressions served on the Google display platforms were not actually seen because they were served outside of the browser window
Google gets $US55 billion a year, roughly, in ad revenues. A huge chunk of that was paid for ads that no one saw, Google’s study implies. It is worth bearing in mind, however, that many of these impressions are sold on a cost-per-click basis, so not all the ads that are served and go unseen are being paid for.
Google Just Admitted More Than Half Of The Ads It Serves Are Never Seen | Business Insider
Guess this isn't really news but when you put the dollars in perspective, is google the worlds largest scammer?