Oddly enough, the reason these folks are failing is that Google's CPC (the money they get for an advertising "click") has gone down Year over Year for the last 13 quarters. What that means is that if your web site depended on advertising from Google (and most do), and your traffic remained constant, you have seen a 33% drop in gross revenue over that same period. Google doesn't call out their click fraud numbers, but they do improve their ability to detect it over time, which means your "quality" click through rate has been going down as well, for a double whammy. So unless you can improve volume, you die. In their Q4 report[1] they make this note:
Network paid clicks, which include clicks related to ads served on non-Google properties participating in our AdSense for Search, AdSense for Content, and AdMob businesses, decreased approximately 11% over the fourth quarter of 2013 and decreased approximately 7% over the third quarter of 2014.
A third less advertising revenue on a 11% fewer clicks over all? Serious pain.
As of the fourth quarter, Google also mentions it is paying nearly a billion dollars a quarter ($968M) to get search traffic. If you're a GigaOm and your traffic is already generating less revenue and fewer clicks are getting through, you can't really add insult to injury by paying people to send you traffic.
[1] http://investor.google.com/earnings/2014/Q4_google_earnings....