• by Laurie Sullivan  @lauriesullivan, November 11, 2014

Google has developed technology that can detect when ad slots are deliberately "hidden" from view on a Web page, and keeps the ads from serving up in those slots. The feature, built from the company's spider.io technology into DoubleClick Bid Manager, automatically prevents advertisers from buying hidden ad slots.

Google's technology can blacklist suppliers of hidden ads, filtering them before they are ever bid on, so advertisers won't buy hidden ads.

The majority of non-viewable ad impressions are legitimate ads intended for consumers to see, but were not viewed because of ways people interact with content on the Web. Products like Active View help advertisers and publishers address this by giving actionable reporting on ad viewability.

Hiding ads inflates impressions and revenue, so the fraudulent companies can show more ads than an actual page can hold when displayed properly. Brands end up paying for ads that have no chance of ever being seen.

Google currently blacklists 2.6% of the inventory accessed by DoubleClick Bid Manager across exchanges, but percentages vary by provider, explains Payam Shodjai, Google group product manager. Shodjai describes different methods fraudulent companies do to create what it call "hidden ads," one type of fraud identified in the IAB's Anti-Fraud Principles and Proposed Taxonomy.

Fraudulent companies create sites and stack multiple ads in one ad slot where only the top ad is visible. They also may adjust the page style to make ads completely invisible. The typical approach is to create a very small iframe to serve ads, making it impossible for a user to see. Others create adware that can inject hidden ads into a Web page, without the publisher even realizing it.