When I purchased the digital version of Diablo III, I was given a passkey to download it.
While I know I need a Battle.net account with Diablo III activated on it to play the game, does this passkey mean I need to own the game in order to even download and install it? If not, can I give my passkey out, or is it only usable one time? If it is a one-time download, is there another way to download the game without the use of passkeys?