If you’ve visited iTunes recently, you may have noticed something different about the “Top TV Episodes” section.  Currently, the three best-selling shows aren't episodes at all, but an independently produced series, Dr. Horrible’s Sing-Along Blog, written and directed by Joss Whedon (Buffy the Vampire Slayer, Angel, Firefly).

Dr. Horrible is outselling the likes of Hannah Montana, Army Wives, and other traditional fare. Although no official sales figures exist (a call to Joss Whedon’s office went unreturned), the episodes were watched almost two million times in five days when the episodes were offered for free on www.drhorrible.com.

If only one quarter of those viewers purchased the show, half a million people could have downloaded the series. At $3.99 for the three 13+ minute segments, Whedon’s company, Mutant Enemy, may have raked in $2 million for a series with a budget of a low six figures.

Thanks to iTunes, this may be the beginning of a paradigm shift, where television shows will be freed from network control and put into the hands of their creators.

According to Mike McGuire, vice president of media research for technology research company Gartner Inc., “[The success of Dr. Horrible is] a manifestation of …the lower cost of production and the nearly zero cost of distribution. Distribution with iTunes, which is amassing and aggregating large audiences, is a no-brainer.”

iTunes gives a small production company advantages that traditional media doesn't—not the way viewers watch television, but how they pay for it. The idea for Dr. Horrible occurred during a four-month strike of the Writer’s Guild of America, where some of the issues revolved around compensation for new media. If independent companies are paid directly by the viewer, the problems with missing residuals are automatically nullified.

Another advantage over traditional media: no money was spend on advertising. The series’ popularity sprung from word of mouth. Also, director Whedon and stars Nathan Fillion (Firefly), Neil Patrick Harris (How I Met Your Mother), and Felicia Day (The Guild) each have their own substantial fan base.

Although hiring talented writers and actors, combined with spending money on slick production values, will limit the number of web series that earn back their costs, Dr. Horrible proves that it doesn’t take a large studio to make a good show…or to make money.

“We’re only going to see much more of this,” says McGuire.