Remember this:
https://www.youtube.com/watch?v=_PV0vWjoY8M
DHL had the world wide network, experience, and the consensus was they were going to put a huge dent into the US market. They didn't.
I don't scoff every start up, and businesses grow and evolve. Part of Amazon's success has been being able to work around brick and mortar businesses and reaching directly to the consumer. I have an account there, and appreciate the convenience. The amount of moving parts and regulation, however, in a transportation company means I think there are issues and problems UPS and FedEx have long since smoothed out that Amazon will have to overcome. I'm not saying they cannot. I am saying I don't quake in my boots for my job must because some financial writers who worship Amazon think its automatically going to be a success. I use an Ipad, not a Kindle. I use an iphone, not a Fire smartphone. Amazon should be respected for their size. They are not flawless, however, and have stumbled in many areas. I think this move is largely a huge negotiating ploy to lock in long term shipping discounts. Even if they lose some money contracting boats and other shippers if it forces UPS and FDX to hold the line on rates for their services then Amazon still can win something.