Amazon is on the cusp of opening its high-tech cashier-less store. In a bizarre twist, it's the Pikachus that were doing the choosing in a test for Amazon's new storefront. the cashier-less store is called Amazon Go. Customers scan their Amazon app as they walk in. The store uses cameras and sensors embedded in shelves to track what customers pick up, then charges them for what they took when they walk out the door. While the tech has improved greatly, there are still challenges.