Click Forensics is obviously a biased party when it comes to assessing the extent of click fraud. However, they are selling a service and they must be getting refunds for some of their customers. So it begs the question:
Is anybody getting significant refunds from using a service like this? From AdWords? Yahoo? Content sites only? Lower tier search partners?
My spend has been increasing steadily and even a 5% refund each month would be significant.