Cowboys stadium is a big risk -- will 55,000-60,000 Americans go to see a Canadian and Brazilian? They would need to load the rest of the card up with quality American fighters to make it sell out I think. If an American on the main card / co-main even goes down with an injury, that could spell disaster for the event. Just look back at some attendance numbers from numbered PPVs in the USA, they haven't sold out an arena show in a while, and they are in some cases giving out 1000s of free tickets to inflate attendance numbers.
If it's done in Toronto, they could sell 60,000 tickets even if it was just GSP/Silva on the card.
ur trippin.. americans are the least racist/patriotic fans when it comes to mma.. they rally behind who they like as fighters/individuals rather than who is a fellow countryman.. this would be the biggest fight in UFC history, you cant compare it to the average fight card held in vegas..