"This actually means that the final answer should be "Sony's games aren't different enough""
Well, if you look at the exclusives the xbox 360 has at the moment, most of them are shooters. It should be that "microsoft's exclusive games aren't different enough" or more respectively "lacks variety". There's more variety in sony's exclusives than there for microsoft's.
Anyways, the most valid reason I could think of concerning games like killzone 2 underperforming in sales is the lack of advertisement.







