Anyone who is determined to cost you money could probably do so by using different IPs and clicking at different times. There's not much anybody can do to stop them.
I don't think looking at the conversion ratio alone can determine it. It could be your selling page is poorly worded or maybe your ads are not targeting the right visitors, etc. So how do you determine it correctly?
we dont live in a perfect world (yet :P)
The other type of click fraud which affects high dollar keywords involves AdSense sites and/or fake search partners. In my fairly tame adult campaigns, I just had to keep knocking bids down to 5 cents on the most heavily hit keywords and relying on more imaginative phrases to promote with.
Like spyware, stealware, spam, viruses and identity theft, click fraud is ubiquitous and is generating cottage industries in response to its proliferation. I just read of $75.00 an hour spyware removal services. Likewise, there are subscription services, etc. that will look for fraudulent clicks. I don't know how the reliable the services and software are. Others here, no doubt, have no choice but to use these click fraud monitoring services.
I still manage to make money, but looking at my logs, I know I make a lot of "donations". If I were to spend more time tracking it down, I wouldn't have time for development.
AdSense abuse is so blatant; it's going to hit the fan someday. I hope Google is ready for the fallout. Keep in mind that Google probably is one of the more vigilant PPCs concerning click fraud too.
Whether it's an impressionable young person in a chat room or a credit card #, if it's out there on the internet, it's a ripe candidate for exploitation somewhere in the world.
patient2all
