In his blog, Sanders Says, Tim Sanders makes an interesting observation about marketing films. He points out that "An Inconvenient Truth," which is mostly a talking head-Powerpoint format, and "The Secret," which is also mostly talking heads (as well as some cheesy 'historical re-enactments') were both sold as movies, not direct-to-DVD productions, and this raised their status.
In the case of "An Inconvenient Truth," it actually had a cinema release.
"The Secret," which "reveals" the secret of the ages: namely that you get what you think about most, was initially distributed as a download, and later as a DVD, but the people who made it and marketed it always referred to it as a movie. It benefited from the hype that the secret was supposedly supressed by some kind of powerful cabal, which feeds into the conspiracy theory mindset even though its nonsense. In fact, The Secret re-treads ideas that were hugely popular in the first big personal-development movements of America in the 1920s but went out of fashion when hard times hit (even though lots of people were thinking positive, the Stock Market crashed--or maybe it was partly because people where thinking too positive, at least about the price of stocks).
The genius of the The Secret is not its content, but the way it was marketed: the makers interviewed many of the top self-development gurus and then got them to market it for them to their huge mailing lists and popular websites. The gurus get more exposure (and a commission?), the producers sell a lot of downloads/DVDs and, now, spin-offs.
Anyway, for students of marketing, both films hold some useful lessons.