first, is click fraud really that big of a deal with regards to an affiliate marketer? does it really account for a lot of clicks? second, if so, what programs/tools are out there that prevent/report click fraud? are these programs free?
have you ever clicked on a competitor's ad?? take a look at my blog ... there's a banner in the top called adwatcher I recommend it click fraud happens .... unfortunately
Adwatcher looks great... I'm just getting started with PPC though- what % of your customers who visited your site via PPC buy something before and after you started using adwatcher?