My commercial drone experience is primarily with multispectral imaging, surveying, etc. Basically, data collection.
I have looked into crop spraying drones (like the RMAX or the recently announced DJI), but it just doesn't make sense right now. Payloads are hard. I can map 400 acres on one battery in 55 minutes with perfect weather/no wind. Add a 2nd camera, and that goes down to about 280 acres and 40 minutes. Add 8mph winds, and I'm lucky to get 35 minutes. There are just so many variables before you even get to the point of worrying about safety and crazies on the ground, that I don't see the appeal. I can deliver a beer to my co-workers house 1.5 miles away, which is hilarious, but it sure as shit isn't practical.
What does make sense (to me) is having an enourmous warehouse outside of a city, with corner drop shops (think Starbucks level of locations) where you can order something online and pick it up from your nearest drop shop 45 minutes later. I can't speak on the financial logic of that approach, but it makes a lot more sense to me than trying to develop a drone delivery system for home delivery.