Disney-owned ABC is the first (and so far, only) television network to offer an App Store application for watching their shows free of charge -- and the effort appears to be paying off.

The Wall Street Journal examines the success of ABC’s app after the first 10 days it was made available for the iPad, noting that the app has been downloaded 205,000 times -- the equivalent of nearly half of the 450,000 devices sold by Apple thus far. ABC offers free streaming of its most popular shows through the app, with five 30-second ads inserted into each hour of programming.

iPad users have watched “at least part” of 650,000 television episodes, generating what ABC calls “several million” ad impressions. The precise number is still being calculated, but the network is apparently quite pleased with the early results.

Among the advertisers featured on the ABC iPad app are familiar brands such as Clorox, Lexus, Apple’s U.S. cellular partner AT&T, Heineken, Sears and Target. The spots are similar to the same 30-second format used during regular television programming, although ABC plans to begin selling more interactive advertising beginning in the fall of this year.

Also on deck: Advertising opportunities for ABC’s local affiliates, which would allow them to provide area-specific spots based on a user’s iPad location -- likely a concession to affiliates nervous about the oncoming march of digital programming that may someday make them less relevant.

As popular as the ABC iPad app is, the goal is ultimately to get users to either buy more of their programming through iTunes -- the app includes links to purchasing episodes from the iTunes Store -- or to watch more of the content via television.

“Not every viewer is going to buy every episode,” explains Disney-ABC Television president Anne Sweeney. “Not every buyer is going to stream. This gives them the convenience of getting what they want, the way they want it.”

The ABC iPad app took 12 in-house software engineers a total of five weeks to build after the Jan. 27 announcement by Apple. Despite Apple CEO Steve Jobs being Disney’s largest shareholder, ABC didn’t receive an iPad prototype to work with during the creation of the app.

Thus far, the most popular show streamed from the ABC iPad app is the March 31st episode of the sitcom Modern Family -- which ironically centers on one character’s lust for an iPad.

(Image courtesy of The Wall Street Journal)