There is no longer any need to post physical Amazon and iTunes cards when selling them on Cardyard. You now enter the redeem codes (claim code according to Amazon) into Cardyard when listing them on the site. For more information see
There has never been a better time to sell your unwanted Amazon and iTunes vouchers for cash. To help recharge your wallet during the summer mayhem, we are paying 90% face value for Amazon gift vouchers, and 80% for unwanted iTunes cards. We will hold these rates until the end of July.