commercial industry. i can see you re excited. a christmas present for you. there you go. another piece of technology that could change the way we shop for groceries. the man behind skype pushing a plan to use robots to bring down the cost of home grocery delivery. cnn s business correspondent samuel burke and he checked out how it works. reporter: the last mile of delivery is most expensive. so companies around the world are working to make that final stretch more efficient, faster. they re experimenting with drones, drivers and now, pardon me, self-driving robots. the most expensive because there s a huge van starting and stopping and the driver is getting on and off and knocking on doors and that takes time and that s something that the driver needs to do for every person. reporter: home grocery delivery services like fresh direct and amazon fresh are convenient but not always cheap.