I think it's because of the DLC, and the fact that the PS3 has been relatively floundering in America.
If this were a racing game or a jrpg, it would have probably sold better on the PS3.
GTAIV is a killing game. Which console sells those games better?
I don't need your console war.
It feeds the rich while it buries the poor.
You're power hungry, spinnin' stories, and bein' graphics whores.
I don't need your console war.
NO NO, NO NO NO.