deadsea - 2:03 pm on Aug 28, 2012 (gmt 0)
If they are clearly marked as "sponsored", shouldn't that be enough? The spammy links are the ones that are sold placed on a page in a manipulative manner. Not the ones that are clearly labeled.
I understand that nofollow is a bit more machine readable for Google, but discounting links around the word "sponsor" wouldn't be that hard to implement either.