Google AdSense is slowly starting to roll out their Referrals program for more products than just their own (e.g. their own Google toolbar). As opposed to the usual pay-per-click Google ads, these AdSense ads will be pay-per-action: like with other affiliate programs, you’ll be able to make money only when a sale – or some other kind of action, like a sign-up – is made from your website’s referral. You can now
sign up to be part of the Beta program.
