Amazon has a lot of questions to answer about its new drone service (AMZN)

Amazon officials left a lot of questions unanswered when they announced the company's new drone-delivery service this week.
The drones' physical and technical limitations would seem to significantly constrain how and where they'll be used.
They also would seem to require Amazon to build out a vast new network of distribution centers and to amass a huge drone army.
Running such an operation would likely be a tremendous operational challenge — and that's just one of many challenges facing Am