Joss Whedon's Distribution Strategy for 'Dr. Horrible's Sing-A-Long Blog'

I watched all three episodes of 'Dr. Horrible's Sing-A-Long Blog' last night, and enjoyed it more than just about any other video content I've seen that was made especially for the Net.

Variety notes that this was a project that Whedon and his brothers worked on during the writer's strike earlier this year. Cynthia Littleton notes:

"Dr. Horrible," which was shot over seven days in high-def vid at a budget in the very low six figures, tells the story of an underdog supervillain, played by Harris, who maintains a video blog to chronicle his efforts to be accepted by the Evil League of Evil. Horrible also has a softer side, as we see when he battles his arch-nemesis, the two-faced Captain Hammer (Fillion), for the heart of a girl he meets in the Laundromat (Day).

Whedon directed "Dr. Horrible," and co-wrote it with his brothers, Zack and Jed, and Jed's fiancee, Maurissa Tancharoen (Jed and Maurissa are writing partners and on staff of Joss' upcoming Fox drama "Dollhouse"; Zack is a scribe on the new J.J. Abrams' Fox skein "Fringe.")

Joss and Jed also penned the music and lyrics to "Dr. Horrible." Much of the musical recording was done at Joss' home studio "with my kids running around." Filming was done on location in Los Angeles at the end of March and some on the Universal backlot, on the New York street set a few months before it was destroyed by a fire.

The first of the three installments appeared on the Dr. Horrible site on July 15th, and the last was posted on July 19th. The video was hosted by Hulu, but there were no ads at all. All three videos disappeared at midnight last night. (Whedon explains his Master Plan for the project here.) Now, they're available on iTunes as paid downloads: $3.99 for the whole series, or $1.99 an episode. There's also Dr. Horrible merchandise for purchase.

All that is great... I just wonder about the last part of Whedon's distribution strategy: the video will only be for sale on iTunes through July 29th. After that, it'll vanish and later appear as a DVD.

What's the logic for making it unavailable to the legions of folks who'd be eager to buy it in digital form? (Let me answer my own question: to make the deal more enticing, exclusive, and profitable for a DVD distributor.)

Correction: The Dr. Horrible folks say, wisely, that the videos won't vanish from iTunes. (Thanks, Kendall, for pointing this out to me.)

Your thoughts?

Here's an interview with Whedon from Wired.