The New York subway system is taking full advantage of its plan to sell all flat surfaces for advertising, including the outside of trains. The latest and most appropriate sponsor of the metal cattle car that you squeeze yourself into every depressing morning: Mad Men, the acclaimed show about advertising! Even if you barely miss your train as it pulls away, leaving you frustrated and abandoned, you'll still be educated about the existence of Mad Men. Sweet. More pics of the hellaciously busy interior of these message-wielding cars, after the jump.