Today Google Pulled Plug on Adsense Referral ads and the Referrals code is no longer displaying ads on the web sites. Last month Google announced that they are going to retire Referrals program by the last week of August and as said they retired them today.
If you looking for alternatives to Referral Ads then it is worth to check Microsoft Referrals Ads which is opened to everyone a month ago. With Microsoft Referral ads you can earn money by promoting two of the its products – Windows Live OneCare & Windows Live Toolbar.
You will earn 1$ for Windows Live Tool bar and 3$ for Windows Live OneCare on every successful download and installation on a computer based in US.