Just for the fact, it wouldn't be 12M.
33% of the original would be bought again.
The real number would then be 15M.
15*0.33 = 5
15+5=20 which is roughly the number of 360s. Therefore, it would be around 15M, not 12.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS