On Monday, December 2, 2013 5:21:47 PM UTC-5, Morgans wrote:

The drones in those pictures generally have a very short duration; probably
in the order of 20 to 30 minutes. I don't see them doing much remote
delivery.

First of all, the UAVs need to be autonomous (no human pilot).
Now imagine a FedEx truck driving slowly down your suburban street with six UAVs departing and returning to the rooftop flight deck (complete with autonomous parcel loading robots and recharging stations.) Jetsons!