Really, this is a stupid time to have "black friday" because you're so upset at your family for making your thanksgiving hell that you get them crap for Christmas and later feel guilty and regret it and have to go out and buy them something else the week before Christmas, when the stores are crowded with other people doing the exact same thing.
Also of note: retailers sometimes understock the shelves to create an illusion of scarcity. That "last item in the store" that you just bought was probably one of many "last items" sitting in the store room.
Sometimes leads to the trampling/stomping of Wal-mart employees
Tim: Why would you wake up at an ungodly hour to go shopping?
Jim: ...Shut it...