The "roommate discount"

Apparently the New York Times gave MoveOn a 60% discount off regular rates for the infantile ad that has been the subject of so much attention this week.

Maybe the 6 figure difference was written into the opinion page budget? The ad was, after all, just an expression of the paper's editorial position, it wouldn't be fair to charge full price now would it? Do they charge Paul Krugman for his space? I think not!