A careful reading of Google’s announcement about click fraud reveals that they really say nothing about the levels of actual click fraud.
Google was careful to comment only on the level of invalid clicks that they actually catch, not the level of click fraud itself. Here is what Google actually says
1) It’s automated invalid click detection find less than 10% of the click are invalid.
2) Manual reviews of invalid clicks reported by advertisers accounts for fewer than 0.02% of all clicks.
3) What they are talking about is invalid clicks, not fraudulent clicks. Fraudulent clicks are a subset of invalid clicks.
So, lets say there are 10,000 click in the system. Google will automatically filter less than 1000 of these clicks as invalid. Advertisers will report some number of clicks as invalid. After manual investigation, Google declares fewer than 2 of them are invalid clicks. But in actual fact, there may have been 2,000 invalid clicks in the system. Google and the advertisers just never noticed them. I’m not trying to say that the actual level of click fraud is 20%, it’s just that it could very easily be somewhere above 10%.
A lot of headlines about this story are very misleading. For example Danny Sullivan’s headline on SearchEngineLand is “Google: Click Fraud Is 0.02% Of Clicks“. Google never makes any claims about click fraud, 0.02% number really is really the number of invalid clicks found after manual review as a percentage of all the clicks in the system.
Search Engine Roundtable’s headline was “Click Fraud is 0.02%, Invalid Clicks 10%, $1B Lost To Click Fraud Yearly“. Again Google claims nothing about click fraud let alone 0.02% click fraud. This headline makes it seem like almost no invalid clicks are fraudulent clicks, which again is wrong. Google said nothing about what percentage of invalid clicks were click fraud.
Again, to be clear, Google never argues what the actual level of click fraud is, just the levels that they identify as invalid clicks.