Just checked the numbers and the Sonic exclusives thing is hardly significant in the slightest for Sony/Microsoft btw.
http://www.vgchartz.com/gamedb/?name=sonic&publisher=1452&platform=PS3&genre=&minSales=0&results=200
Every Sonic game on the PS3 sold 6.14 Million units combined. As a comparison, because EA is part of the thread, Battlefield 3 has sold 6.4 Million units on PS3 alone
Every Sonic game on the 360 sold 5.7 Million units combined. As a comparison, because EA is part of the thread, Battlefield 3 sold 6.8 Million units on 360 alone