Tell me about your PPC fraud recovery experiences

How often do search engines pay up?

[snag]

One of my clients spends quite a bit on PPC every month, and is sick to death of the obvious PPC fraud that costs him money every day. I know there are lots of solutions out there, ranging from free open-source software to services that charge a percentage, but I'm curious about everyone's experiences before we invest a lot of time or money.

What does it take to get a search engine to admit fraud took place? Does a bunch of single-page views provide enough evidence, or does it all need to be from the same IP? What about obvious statistical anomalies, like conversions that suddenly drop or much higher than average bounce rate? Does having a little javascript that pops up to 'warn' potential fraudsters actually work as a deterrent, or do they even see it (since they probably all disable javascript)?

Has anyone tried to recoup their fraud losses and simply given up on it, or is it worth the effort?

[gregbo]

If you go to the Yahoo Search Marketing, Pay Per Click Engines, Google AdWords or AdSense forums, you'll see several threads on PPC fraud recovery (usually containing "click fraud" in the title, descriptive text, or somewhere in the thread). The methods people use vary, as do the levels of success people have getting refunds. I have never heard of anyone getting a complete refund. You may get some money back.

IMO, your best weapons against click fraud are:

* Reduce your spend
* Follow discussions on the topic from people with a technical background (e.g. people who study botnets)