So your friends are trying the game, so you static group cleric is out sick, or you just can't find a dang monk when you need one.
You have given us hirelings. How about the ability to actually play a pre-made toon.
You know to rent out a level 4 Toon to help a bud level up since you have 10 capped toons. (Or no toons in thier level range at least). Or a cleric for your static group. Make a series of premade toons that we have the ability to fully play not just add to a group.
There of course would have to be certian restrictions, like can't do raids, no bound loot, and other things I haven't thought of.
But a starting point for a conversation at least.