doorstep是什么意思？

More than drones dropping a new supply of underwear on your doorstep, Apple's massively successful brick-and-mortar-and-glass retail stores and Amazon's small steps in the same direction are what should keep old-fashioned retailers awake at night.

So, despite all the talk about drone deliveries to your doorstep, all the retail executives expressing anxiety over consumers going online, and even a Presidential candidate exclaiming that Amazon has a " huge antitrust problem, " the Census data suggest