There will be losses, as you may expect, in the retail trade, but there will also be growth in the industries that will be required to support the growth of Amazon. Couriers, the vehicles they use, fuel, tyres, servicing, the drivers need to eat etc. The list, I imagine (without much thought) could be very large in terms of support of said growth. The drones that are mentioned, well, someone needs to make them, and make the parts that make them...and so on..