Marketing movies was never much of a "long term" activity for movie studios, and most historically have used broadcast to quickly hype an upcoming release. It's just how things typically worked, particularly when the financial success of a film is all about the opening weekend. As the years have passed though, this approach hasn't yielded the kind of box office receipts that a studio craves. With their young, key audience harder to reach, it's interesting to see how these marketers are getting much more inventive.
This "inventiveness", in keeping with Henry's observations of fan culture, was arguably first tinkered with when Hollywood took a mediocre, kitschy movie like Snakes on a Plane and decided to work slowly on building a fan base before the movie's release. Not all agree that this movie was truly a success and it's doubtful that it will become a cult classic. But this type of fan marketing hasn't been jettisoned, and recent activity to promote The Dark Knight demonstrates what appears to be a great case study of how to apply fan marketing to the film business.
Of course it's easier with a property as perfect as this, particularly with its enormous cult following. But kudos to Warner Brothers as they incorporate unique fan marketing, and engaging alternate reality gaming techniques into its promotional mix.
So far the campaign seems flawless, working it's captivated audience with leaked information, cryptic web puzzles, and coordinates to real world locations. Beginning more than a year before the movie is set to release; this is a great transmedia story to watch. One that builds from Snakes on a Plane, I Love Bees, and Audi's "The Art of The Heist" and takes things further.