actually it's the problem - fraud clicks are difficult to detect! How google does cope with this trouble?
They lose advertisers.. how would you feel if you had to pay Google for all the fake clicks, while you were expecting quality visitors? I don't know how they detect it but I'm happy they do everything they can to protect their advertisers
The advertisers will know that most of the money they are spending on advertisement is fraud,then they will abandon google.
I am sure google works very hard to detect fraud clicks. I am sure they have many and redundant methods. Google makes their money of advertisement, if they don't protect their clients, they will lose them. If they lose their advertisers, they have no business.
really.. its not a bad question, look, yahoo is one of the best business on the net, and they have a poor ad network cause they dont know how to control frauds etc... they cheat advertisers, and anyway, they are still there living...