There really isn't any argument saying that the Xbox does not rely upon the sales of shooters to make their numbers.
Are they not generally the best selling titles on the platform?
I don't see what the big deal is here.
Shooters sell worse on the PS3.
Look at the top selling multi platform shooters on the PS3 compared to the Xbox and then look at the numbers for PS3 exclusive shooters. They don't sell anywhere near as well as the Xbox exclusive shooters.
They have to pick up the slack in other genres.







