I put in my code and I guess it accepted it, but at the last page on the MOH beta site does it give you a link to download the beta? Just had a blank space in the middle.
I think it works like this:
You trade in Game X for $20.00, then an additional $6.00 because of the 30% power trade, and then another $2.00 for the edge card. In total you would get $28.00. You can't stack more than one offer unless of course you get someone who is unfamiliar with store policies...