Amazon Go stores (in SF, not sure about the other 3 cities) -- https://en.m.wikipedia.org/wik... -- are micro grocery stores without cashiers/tills. Scan your Amazon Go app barcode on the turnstile as you enter, pick things off the shelf, put it into your bag, and walk out through the turnstile.

As you're walking out you get an emailed summary of your shopping with how much time you spent shopping prominently featured with a feel good message accompanying it. This does two things at once: Emphasizes time spent shopping -- because longer term when they build out these newer grocery stores that'll be a big draw -- and adds a gamification aspect to shopping -- how efficient/fast can you be at shopping can be a self-competition thing and at any point they can create a 'leaderboard' of shoppers ranked by time spent, money spent, etc.

These Go stores are also filled with folks who don't mind beta testing stuff. These future concepts being talked about can be tried out in these curated stores. A very useful real-life place to weed out the good ideas from the bad.