A new pay-per-action model could help Google lead the way in addressing the industry's problem with click fraud.
Google is beta testing a different business formula for its AdSense product that eases up on its lucrative pay-per-click model in favor of a pay-per-action model. The new program could help address the click fraud problem that dogs the per-per-click sector of the online ad industry.
The idea with the beta test is to provide advertisers more latitude with ad contracts by stipulating payment only for pre-determined actions that result from a Google ad, such as a certain product purchase or signing up for a newsletter. source