If you want to be practical just let them fly your account. 
Lusche is right. If they have already blown their two week account, they didn't know about AH, they may not have a computer strong enough fro AH, they might be short the coin for a AH account, They are unsure about the AH experience, the reasons can go on and on.
Reread the original wish.
The only reason not to do this is an abuse of the privilege. Hopefully a small fee added to the normal user might deter some of that and that the user name would be the same but with say an add on like HG. Randy1HG as an example or maybe CG for computer guest.