Originally Posted by
Eastbay1K
I'd really not want to screw the restaurant participating in the program, who is going to suffer from accidentally taking a cert with the same number twice.
While I totally agree that one should not intentionally try to reuse a certificate that has already been used, it is not the restaurant that gets screwed. The money one pays for the certificate goes to restaurant.com, not the restaurant itself.
Every time I have used a certificate, the restaurant has kept it. I print the certificates right when I buy them and put them in a folder. That way, if I have a copy of the certificate, I know it has not been used.