Since its first season, Mad Men has become notorious not only for its superb writing and acting, but also for its infuriatingly vague "On the next episode of AMC's Mad Men" promos that air at the end of each episode.
While previews are generally meant to hook a viewer and convince them to keep tuning in, Mad Men doesn't really need to worry about that. The show (deservedly) has a loyal and rabid fan base that will continue to watch no matter how frustrating their teasers are. (Comedian John Mulaney has a particularly great bit on it.)
In a recent interview with Vulture, Mad Men showrunner and "spoiler-phobe" Matthew Weiner addressed the restrictions that he puts on the promo editing department:
“I have tied their hands and I’m amazed at what they do with the restrictions I have given them. Over the years, it’s evolved into this semaphore of storytelling. We pay so much money for that music at the end of the show that I don’t really understand why we even have a promo for next week. I don’t want to reveal anything!"
The specifics of his restrictions:
"Please don’t mention anything beyond the first twenty minutes of the show, please don’t spoil this story, please don’t spoil that story."
So what happens when you edit together all of the promos from season six? Do you get any sense of a cohesive story? In a word — nope. If you were to watch the teasers alone, you'd probably think Mad Men was a show about a group of strangely dressed people who spend all their time opening doors for surprise visitors, staring sadly at glasses of scotch or sighing into telephones.