encyclo - 12:47 am on Jul 1, 2008 (gmt 0) See also: Doubleclick Performics is now Google Affiliate Network [webmasterworld.com]
From the AdSense blog [adsense.blogspot.com]:
We're constantly looking for ways to improve AdSense by developing and supporting features which drive the best monetization results for our publishers. Sometimes, this requires retiring existing features so we can focus our efforts on the ones that will be most effective in the long term. For this reason, we will be retiring the AdSense Referrals program during the last week of August.
See also: Doubleclick Performics is now Google Affiliate Network [webmasterworld.com]