Cardyard is effective if you are buying something online from John Lewis, Amazon (or whoever you can get a card for) and want to get a few extra percent off of the price paid in addition to any other discounts you might have secured. The only drawback is that buying Amazon codes recently has been somewhat hit and miss and quite often a code received hasn't worked, with Amazon saying it has already been applied to another account. Each time this is resolved and refunded by Cardyard witin a day or two but it is still a hassle when you just want to get on and buy something.