Amazon's Self-Service Stores

There are some really interesting things that Amazon are doing. I've been to one of their self-service stores in Seattle, which is where they're pretty much located. You basically download the app and then you use it to go into the supermarket and pick whatever you want. It knows what you've got in your bag before charging you for it. Marks and Spencer are doing a similar thing here but just don't have the tech as Amazon does.