Costco is the only place where I've seen this. I don't understand how it gets an authorization for any amount that fast, since it can't know the total while the cashier is still scanning items, and it's Costco, so it could be anywhere from $50 to $5,000 so surely it's getting the authorization after the transaction finishes? The flow is almost perfect. I have them scan my Costco membership, I use tap to pay on the card reader, then I or 2nd cashier move to organizing the items into the cart, and then the cashier hands me a receipt with basically zero wasted time.