It’s ok that Blizzard is fighting gold sellers and offering something unique for having an authenticator. But please make it work on level 30+ only. 4 extra slots at level 1 will be too much of a gameplay change. And accounts with level 30- characters only for sure won’t yeld a lot of gold when hacked.
I like to level up new characters on no-mail-from-main challenge just for fun, so if it doesn’t have level restriction, then II’ll have to disable the anthenticator on my account, which I had for so long.