I can imagine Bezos implementing it on a very small scale for publicity's sake.
i.e., He invites CBS, FOX, CNN and a few others to witness the "Birth of Amazon Drone Delivery" in a few years. He has a well choreographed delivery program to three or four well-rehearsed homes 1 or 2 miles away that are free from obstacles, pets, children, power lines, and other areal and ground potential hazards. He deploys the drones, the cameras roll, and we see them deliver the packages flawlessly near the front doors of the homes and then fly back to Master Bezos. Good Drones! Well done!
Doesn't have to go any further than that. Amazon delivers packages via Drones. Mission accomplished. Amazon is an amazing company on the cutting edge of consumer product delivery. Stock rises 20 points.