Quote Originally Posted by Abriael View Post
Accounts are region specific. If you have an european SE account, an US key won't work. The fact that the servers are worldwide doesn't change that.
if you are from the US and cant find a cheap key there you can make a european account and add a european key..

you'll still be able to play with your friends from the US, and since the payment methods are global it wouldnt mather at all..

An account is just something you create on the website, it binds you to the specific region you select, but you can always just make a new account, if you havent bought the game yet it wouldnt mather ;-)