Yea it all depends. Say A game costs $60to buy and it sells 1million. So that's $60 million but u have to take account on other expenses such as shipping to retailers and the retailers getting a chunk of that money. And the other expense include advertising and maybe paying websites to review the game.

Above I'm a proud Gran Turismo fan, not a Sony fanboy, and now a proud 360 owner, but sharing xbox live accts ATM
End of 2009 Predictions (made Jan 1, 2009): My predictions were pretty accurate, the 360 was over and the Wii was just under.
Wii: 65 mil (yea I'm crazy) 360: 35 mil (its getting there) PS3: 30 mil (the slim better do well)
End of 2010 Predictions (made Jan 7, 2010):
Wii: 81 mil 360: 47 mil PS3: 45 mil







