Having just started some high value (to me) ads on a few PPC networks I'd like suggestions on how to spot click fraud.
So far the clicks from Google have been good, it seems they have a reasonable grasp of the issue (or it could be that I'm in such a low position for the 'big money terms' that the fraudsters aren't seeing my ads yet).
I am having difficulty with a different network though (not Overture as I'm not running ads there). It seems to me that there is a tree-like structure to the 'publishers' that manage to get onto a network:
A Few large, trusted partners>>
Trusted partners take on affiliates, maybe slightly less trustworthy but still O.K.>>
This continues with each level down getting less revenue and having dodgier 'publishers' right the way down to 'ad networks' that pay out by paypal when you reach $1!
My thoughts are that some PPC networks have no idea how many sites run their adverts. If this is so, then how would you go about detecting click fraud?
I know that many people gave up with the smaller networks some time ago, but I still think there may be value in them if the fraud can be reduced.
So far I have seen click-bots and what looks like human click fraud too, these have been easy to spot with the poor implementation of the fraud (same IP for many different terms in a short period of time). It's the sneaky techniques I'm trying to detect.
IMPORTANT: If you don't want to put the advice on a public board then please sticky me, I can understand that people may be reluctant to give pointers to potential click fraudsters.