It seems people are trying to figure out what the deal is with Bob Benson:
http://www.tv.com/news/mad-men-specu...-136682755159/
I like the theory that he's time-travelling Bobby Draper and he's come back to throw Don off the roof of the building, like in the opening credits.
I guess I've worked with too many advertising sales guys in my life because he didn't strike me as anything more that a typical suck-up "Account Rep" sales-weasle.