I saw this note inside my Adsense account "Note: Referrals is being retired during the last week of August 2008, so we recommend that you do not implement referral ad code on your site at this time." but I didn't see anyone talking about it here. They have a whole section inside their Help Center about the end of the Referrals program. Basically, it will end for both Google products and 3rd party products.
Yep. Probably at least in part because of the Doubleclick. Of course, wouldn't you know, I finally found one that was actually converting for me. But overall, Google just never devoted the resources on either the AdWords or AdSense sides to do referrals right, so it's just as well. Not sure why they're ending referrals for Google products, except maybe they feel they don't need it anymore.
or may be google has found a better ad program then referral program. today i got mail from adsense about they are starting double click. although i could not sign in there by my gmail id. seems not yet fully transform to a google product