[numbsafari]

Philly sits halfway between NYC and DC, via Amtrak or I-95. They could get in on the new project to cap the rail yards next to 30th Street Station and find themselves situated between the University of Pennsylvania and Drexel campuses, with Temple University a stone's throw away and Princeton accessible via NJT/SEPTA regional rail.

There's also available suburban sites in Southern NJ and Malvern, PA that are accessible via mass transit, the Navy Yard (which desperately needs a subway spur) and tons of developable/reclaimable industrial space in North Philly.

Given how accommodating PHL has been with Comcast, I'm sure Amazon could get what they need.