really? humm, i would have totally though that most developers set up some sort of automated database or webpage or something to handle all that... is it really common to outsource apps?...
This is a support nightmare waiting to happen. Even with sales below 1000, are you equipped to handle the requests for a serial to be resent? How are you going to tell that this is a legitimate customer? You're now going to keep a sales database as well as the serial database? If someone moves, will they need to tell you their old address?
It is a solved problem, and perhaps not a technically involved one, but you will either have to:
1) spend a lot of time building out the infrastructure so everything is completely automated from purchasing to account and sale management to lost serial retrieval.
or
2) be prepared to manually intervene in all of these cases.
Back when Yahoo Widget Engine was Konfabulator and it was not free, it was sold through Kagi. The experience was good, and when I managed to lose my serial number, it was easy to get it back.
If you want to take a go at it on your own, more power to you, but I imagine it would be easy to spend more time working out a web "store front", sales management database, automated emailers, etc. than you did on your original app.
-Lee