Well, I'm going to give this one more try before I give up
I would think this would be a popular hack... IMO, it is
totally unacceptable to not send the customer any kind of feedback after they give you money.
I get tons of "Am I upgraded?" emails... No communication is sent to the user to let them know they've been upgraded and have access to added perks. Especially "older" users, who expect that some manual process must be done to upgrade their account. I grant many perks when users buy a subscription - but no visible changes occur, hence the confused users.
Also, I get emails and phone calls from users who pay with an "e-check" via paypal. Paypal takes a few days to clear the 'e-check', and their account is not upgraded until it clears. So I get confused users wondering why they don't yet have their added perks/access.
An automated 'thank you' and info email would solve this issue beautifully... I will do anything (almost anything

) for this functionality!