A new startup called KarmaKey wants you to throw out all your loyalty cards.
You’ve probably got a few of those cards in your wallet right now, usually offering you discounts or freebies at your favorite stores if you make a certain number of purchases. Now, instead of making you carry a card around, restaurants using KarmaKey print out a special code on your receipt. You enter that code into the KarmaKey mobile application, and you can redeem it for a discount or other deal at the store.
This is good for customers....