Originally Posted by Gottis

from another board:

For the sake of argument, assume click fraud is real and does account for 50% of Google's ad sales. Yet, still the advertisers buy the ads. Why? Because for them the metric is advertising cost per sale or new customer, not percentage click fraud.

So, 50% click fraud says that if click fraud were eliminated, google could simply double their prices and the advertisers would still find it cost-effective. Sorry, but click fraud won't bring down google (not that you'd find me buying the stock at these prices).