ABC News is unique amongst the broadcasters' experiments online. They create a 15-minute daily newscast separate from "ABC World News" though using the same set and same anchor, Charles Gibson.

"World News Webcast" airs a live webcast at 3 p.m. ET. It's also available for downloading on iTunes a little more than an hour later. And it's popular: In September, there were 5.2 million downloads via abcnews.com and iTunes, according to ABC. So far this month, there's been 5.2 million.

I believe that this effort is succeeding because the webcast appears to understand that its audience is different than the broadcast audience and that it deserves just as professional an effort.

Reuters wrote:

There are the headlines of the day on both newscasts. But owning to a much younger audience, the story selection often diverges from "ABC World News." There are often quick Q&As with correspondents. ..

Some of the pieces have a decidedly new-media feel to them. A correspondent recently shot a piece walking on the streets of Baghdad to explain what it was like to wait in line for gasoline and pay more than Iraqis are accustomed to paying. It was closer to a video blog entry than a traditional report.

... The webcast itself has evolved. There's a partnership with Google that provides the webcast with the top Web searches and keywords. Another innovation is the chaptering and Web links...