Looks like Cashrewards have quietly followed Shopback and launched their own gift card portal.
The Xbox gift cards appears to be the best value as the cashback is more than what is provided by Microsoft.
I'm guessing that gift cards from True Rewards will be added to this portal.
Get cashback when you buy gift cards to use at your favourite stores. Whether you’re buying a gift for a friend, or for yourself, you’ll get more for your money when you shop through Cashrewards. Don’t want to wait? Shop digital gift cards now for instant delivery to your inbox.