I can't agree more.... Infact the likes of Amazon are investing massively in drones to facilitate Easy delivery....
So the days of sending gift boxes with drones is closer than Ever
To answer your question about batteries @mykelade: it All depends on the Sophistication of the drone... Some drones have the "back to home" feature where the drone automatically returns to the user when the battery returns to a certain level
while others indicate low batteries to the user and the user manually flies the drone back to replace the battery