Amazon just opened a grocery store without a checkout line

Shoppers can literally grab and go without paying for their goods at a cash register at Amazon's new smart grocery store in Seattle. SAN FRANCISCO -- Amazon is testing a grocery store in downtown Seattle that lets customers walk in, grab food from the shelves and walk out again, without ever having to stand in a checkout line. Customers tap their cell phones on a turnstile as they walk into the store, which logs them into the store's network and connects to their Amazon Prime account through an app. The service is called Amazon Go. It uses machine learning, sensors and artificial intelligence to track items customers pick up.