I've noticed several grocery stores in the largest cities I've been in (Shanghai and Tokyo) lack carts both due to space constraints and because people visit on their way home either to or from the train station. Shopping carts are mostly necessary/convenient in suburban environments where you have to drive to bigbox stores because you live too far away.
Judging by the area of the city that Amazon Go is in and the ubiquitous housing nearby. I suspect this is the model they're going for.
Judging by the area of the city that Amazon Go is in and the ubiquitous housing nearby. I suspect this is the model they're going for.