Looks good. Some unsolicited advice:
Add an FAQ with plain language instructions and a little humor to disarm people who might think this is a scam (it's not, right?).
Give an estimated timeline for receipt of the giftcard after order.
IMHO I like these services, but trustworthiness is everything and I can't imagine how these get off the ground without some kind of escrow service up front because it's very high-risk.
Thanks a lot for your advice!