amaz amazon's membership cost $300 a year. one of skype's founders believes he can bring costs down with self-driving robots. ♪ what does it have in it different from the cart i use to get my groceries. >> the cart doesn't have nine cameras, but our robot does. and it's six-wheel drive, it has electric motors and various other sensors. the robot is observing pedestrians, navigating on the sidewalk, and needs to be aware of its surrounding. >> reporter: how does it get from the warehouse to the person's house? are you using google maps. >> we are doing our own mapping actually, because the maps that our robots need are quite special. they are more sidewalk maps than road maps. exactly. exactly.