Drone delivery
This is a much misunderstood business IMHO. Unless there are unpublicised developments in range and duration of current technology the use of drones for deliveries can only be for a tiny minority of all orders. Currently the duration of multi rotors is measured in minutes not hours, and their speed in tens of knots. Admittedly fixed wing planes last much longer and go faster, but they require decent sized fields to take off and land. Not many customers will be willing to have their goods delivered by parachute. Landing and taking of again at the point of delivery poses obvious dangers which would be unacceptable to commerce and regulators alike.
In order for decent sized payloads to be carried the vehicle needs to be correspondingly larger, and much more expensive. Currently such aircraft are limited by law to a ceiling of 400ft agl in most jurisdictions where they are likely to be used. The temptation posed by large fairly slow noisy machines to amateur marksmen with shotguns is obvious. The likely attrition from this and other causes would render insurance against loss costly.
I do not expect any serious exploitation of unmanned aerial delivery systems commercially for a very long time. If ever. As a means of securing cheap publicity for Amazon and others they seem to be a sure fire winner.