The company that ran the Obama "homepage pushdown" ad (see a sample ad from Texas) on 16 of its TV news Web sites had just figured out how to post such ads when the Obama campaign called less than two weeks ago.

WorldNow, which runs about 250 news sites, didn't expect that its first client would be a political candidate, said Adam Gordon, the company's chief revenue officer. Campaigns have not spent as much on online ads during the current campaign as many thought they would.

"I just don't think that the candidates wanted to risk dollars in a medium that they view as unproven when it comes to voter action," Gordon said. "They certainly used it for fundraising. It's certainly an effective tool for fundraising."

The ad also ran on about 30 Web sites in Texas and Ohio not affiliated with WorldNow.

Managers at the WorldNow sites could have opted out of running the homepage ad because it pushed their content down or because it was political, Gordon said, but none did. He said he didn't think any stations had concerns about the perception of endorsement.

"I really think those concerns have been put to bed a couple of years ago," he said.

Gordon said this is the largest coordinated online advertising purchase by a campaign during this election.

He wouldn't say what Obama paid for the ads, but said it was a "high-impact, high-CPM (cost per thousand)" purchase. The Obama campaign bought every impression, meaning the ad ran every time the Web pages were loaded.

WorldNow also arranged for some of its sites to run Obama "pre-roll" ads before online videos, though some sites declined to run them because the 30-second videos exceeded their maximum ad length.

Candidates haven't really embraced online advertising as much as some thought they would in this election season, a point noted a month ago by Poynter's Rick Edmonds.

"We have not seen the watershed moment of politicians embracing the Internet like we thought they would," Gordon said. "Maybe in 2012," he said -- though he noted that's what people said about 2008.

Mediaweek Senior Editor Mike Shields, who wrote about the innovative ad last week, said he has heard several theories for why campaigns haven't advertised online more. One is that political consultants are simply more comfortable with television advertising.

Limited funds may have played into a reluctance to spend online, he said. And primaries are local contests, he said, whereas "I think people tend to think of the Web as national."