I agree with you that deliveries to offshore oil and specific functions will be very practical. However, not so sure I agree that economics will prevent 'fresh

I agree with you that deliveries to offshore oil and specific functions will be very practical. However, not so sure I agree that economics will prevent 'fresh grocery' delivery. It will be different vehicles for sure, but the operating costs of a small electric vehicle with 5-10lb payload can be very low (cents/hour). I doubt there's going to be direct farm-to-house deliveries, but instead something that can augment the current transportation infrastructure. Imagine a national grocery chain adopts small electric drones for last-mile delivery. They leverage existing shipping network in place to keep stores stocked, and just send drone deliveries from store-to-house. Actual flight cost for one round-trip store-to-house is going to be pennies.