> This lightweight request signals a 'click' on the server responsible for the Ad, but does so without opening any additional windows or pages on your computer. Further it allows AdNauseam to safely receive and discard the resulting response data, rather than executing it in the browser, thus preventing a range of potential security problems (ransomware, rogue Javascript or Flash code, XSS-attacks, etc.) caused by malfunctioning or malicious Ads.

You might be thinking of TrackMeNot, which does use tabs (iirc).

From google's perspective it operates as a botnet consuming their resources and creating doubt as to the validity of their product among advertisers (disclaimer: I am not defending their business at all). That's the goal, but costing the advertisers themselves money doesn't necessarily follow.