i think you misunderstand those 2 games for the same principle do you?
in wow theres a few thousand accounts in one world while in d3 you will have to open a private(or public, whatever it is...) game in wich you will be listed seperately. its very easy to scan one game with one person in it instead of a giant world with then tousand people in there?
just move the shit away from comparing diablo with wow....