Quote Originally Posted by Oricalcos View Post
They can only be associated with any number of Battle.net accounts at a time, but they will work with whatever accounts they are associated with at that time, they will not show you the auth number for another account.

You link them to the account by typing in the serial number on the back of the device.

Now stop asking questions and buy the device already
I don't want it, I just don't understand how people can say it does anything without being connected in any way to the game. How else is it supposed to work?