In cities, delivery drivers ship 600 packages/day into packet vending machines, vs only 60 regular delivery, and regular deliveries via usps cost less than $2

In cities, delivery drivers ship 600 packages/day into packet vending machines, vs only 60 regular delivery, and regular deliveries via usps cost less than $2 for amazon., So i don't think a drone , in this high density case could offer much savings.