It's difficult to believe that this is FTEs. Very easy to believe it's FTEs, contractors, temps, and vendors. Including warehouse workers etc.

EDIT: I was curious, so I took a peek at their 10-K [1]. "We employed approximately 566,000 full-time and part-time employees as of December 31, 2017." I couldn't find any info on their FTE count with a quick keyword search.

http://phx.corporate-ir.net/phoenix.zhtml?c=97664&p=irol-sec...