Preventing Ad fraud

Question

How does AdSense and other similar services prevent a fraud where publisher click themselves on their ads or employ other more sophisticated strategies in order to generate higher revenue?

Answer 1

The fraud is where other people click on a AdSense link for the purpose of collecting money. Click fraud is the act of clicking on ads for the purpose of costing the advertiser money. It is the same as paying out cash for false leads.

Here's an excellent blog post on the subject.

Google AdSense Fraud - How it is Done and How to Prevent from AdSense Fraud