EA has just stated in their latest fiscal quarter "PS3 with total revenues of $121m, markedly higher than Xbox 360, which generated $73m for EA. "According to VgChartz EA sales much more copies for the 360 than to the PS3, remember EA is saying "revenues" which means money generated from sales not "profit" that said EA is actually selling more games copies for the PS3!
http://www.mcvuk.com/news/35278/PS3-outperforms-Xbox-360-for-EA
So I guess the only answer to higher 360 sales is the fact both VGchartz and MS are couting 360 pirated copies as sales which in case would be something totally expected coming from the Seattle based squad!