A Google AdSense Help thread has one AdSense publisher complaining that there was “a $3,000 deduction” from his Google AdSense account.

Truth is, his actual earnings versus his estimated earnings was $3,000 less. Why? Because 3,000 of those dollars were actually invalid clicks and thus not earnings at all.

A Google AdSense Engineer named Guillaume said:

Of course, the AdSense publisher does not agree his traffic lead to invalid clicks. In fact, he has some solid evidence the traffic increase and ad click increases were legit. But that is a different story.

Lesson learned: Estimated earnings are not actual earnings.

Forum discussion at Google AdSense Help.