pay-per-action beta in the last week of August 2008. As an alternative to pay-per-action advertising, Google offers two products that allow you to manage your advertising on a CPA (cost-per-acquisition) basis: the Conversion Optimizer and the Google Affiliate Network.
The Conversion Optimizer is an AdWords bidding feature that lets you specify a maximum CPA goal for ads on the Google search and content networks. It uses historical information about your campaign to automatically adjust your CPC bid for each auction to help you meet your CPA goal. In addition, the Conversion Optimizer is now supported in both the AdWords Editor and the AdWords API. You can learn more on the Conversion Optimizer homepage.
The Google Affiliate Network, previously known as DoubleClick Performics Affiliate, has been in operation since 1998. Through the network, advertisers can open their ads to all publishers in the network, or select specific publishers that match their criteria. You can set a CPA for your entire campaign or establish custom payment schedules for specific publishers -- such as a higher CPA for a particularly optimal placement. The Google Affiliate Network is currently a separate product from AdWords and AdSense. As with AdSense, publishers must apply and be accepted into the network.
If you're interested in learning more about the Google Affiliate Network, please visit our website.