Because of Japan and playstation fanboys, but the xbox360 has to this point been doing a hell of a lot better than the ps3 on sales (even though the xbox360 had a huge disadvantage in Japan where the Japanese want to support the home team =D). Even if the past 4 weeks it's been outpacing the xbox360 (which that website I link says otherwise) then it still has literally millions of units to catch up to.