The Hollywood Reporter has a great behind-the-scenes history of Mad Men. There is some fun gossip: I didn't know, for example, that show-runner Matthew Weiner started working on the landmark drama while co-writing for Becker.

But the line that caught my eye was this elegant explanation for why you should thank your dreadfully unaffordable cable bill for the golden age of television.

"Cable operator retention"? What's Sorcher talking about?

AMC, like other cable networks, doesn't make most of its money from advertising. Instead, it makes most of its money from simply being on cable. The channel gets a few dimes from every household's monthly bill, whether or not they watch AMC. These dimes add up to several hundred million dollars a year in so-called "affiliate fees." Since only a tiny share of all cable households watch Mad Men, but all cable household pay for AMC, it's hardly an exaggeration to say that Mad Men only exists thanks to the millions of people who don't watch it.

But before it had Mad Men, AMC needed a very specific sort of hit to keep collecting these fees. It didn't need Two and a Half Men or NCIS. It didn't need a mainstream hit aimed squarely at the middlebrow. It just needed a niche hit—something unique and craved by a large-enough, and enthusiastic-enough, audience that Comcast, Time Warner Cable, and other operators would never dream of leaving the network off the bundle.