If you look at KZ2 online rankings, it could give some hint of sales.
Rankings, alltime there are 38600 pages, ten usernames per page 1/38600. So if we do simple math that means 386000 people have played online- worldwide. Not impressive number for such an amazing game.
This is not trolling, i have PS3, look at my past comments, i am PS3 guy, and if you don't trust me, numbers are there, if you have KZ2 you can see it for yourself.
THere are probably some ppl that haven't played online yet, but i doubt that number is 500k+. i doubt it is more than 150k.
Sales are not that good if this numbers are any hint.