They do and they know, I havent been to any other ground where they keep the concourses open after the match, we are lucky to have that and the club certainly make a few quid post match because of it.
Id say in deepest darkest winter especially mid week the concourse can be a bit of a grim affair.
Since we have been at the AMEX I have always stayed back and had a couple of pints then wondered down to the train. Dicks is probably a better option in the winter months though if you want...