If Amazon wants to create its own nationwide warehouse-to-customer delivery network, I imagine they believe doing so will allow them to provide better service at lower prices than the Big 3 established parcel service (USPS, FDX, UPS).

Can they develop such a delivery network? I'm sure they could, but the Capex required to develop the infrastructure to get there would be astronomical.

Could they do it such that they eclipse any of the above carriers in volume in just *two* years? Absolutely positively not, and anybody who suggests otherwise needs a whiz quiz.