The creators of CBS’s “How I Met Your Mother” have made inroads toward solving the puzzle of how to make a Web promotion drive linear ratings.

The CBS sitcom generated an impressive 600,000 additional viewers for the Nov. 27 episode compared with its season average, and an increase of 1 million from the previous week, after it planted a music video performed by one of the show’s characters on MySpace and other viral video sites-all without referring to the show or the network.

Known as the “Robin Sparkles” video and featuring the show’s character Robin Scherbatsky as a teen pop star singing the song “Let’s Go to the Mall,” the music video became an Internet hit following the Nov. 20 episode in which it was featured. Views across MySpace, YouTube, CBS.com and a number of other sites ticked past 300,000 in the first 10 days and were coupled with a huge spike in blog postings about Robin Sparkles and the show.

In the episode, the character of Barney, played by Neal Patrick Harris, is obsessed with finding out about what he believes is his friend Robin’s deep dark secret from her past. He comes across a videotape and says in the show, “It’ll be up and running on my MySpace in … right now.” CBS also ran a tag at the end of the episode urging viewers to see the whole video on MySpace.com and CBS.com.

The show’s creator Craig Thomas believes there is a connection between the ratings rise and the viral promotion, especially because the viral video was the primary differentiating factor week over week. “There is a very good chance we will do it again this season,” Mr. Thomas said. “When you do something and your ratings go up, it occurs to you that maybe you should do it again.”

Mr. Thomas and fellow showrunner Carter Bays conceived the idea for the video independently. “How I Met Your Mother,” the youngest-skewing scripted show on CBS, was not one of the programs earmarked for promotion in the corporate deal CBS struck with YouTube in October.

So as TV executives at various networks wade through murkier returns from their YouTube and MySpace partnerships, the “How I Met Your Mother” example stands out because of the sizable ratings bump and the likelihood that it came from the viral buzz.

The ratings rise also suggests that Web promotion can work, but perhaps is best done with a backdoor approach rather than with more obvious promos, recaps and outtakes. “If it’s built into a specific story idea, people will follow it. Otherwise they can smell the B.S.,” Mr. Thomas said.

Moments later, traffic to the fictional pop star’s MySpace page rose along with Internet blog postings. More than 4,000 fans have since joined the page.

Indeed, this kind of off-the-beaten path approach to Web promotion can especially help a network grappling to get younger, like CBS, said Brad Adgate, senior VP of research for Horizon Media.

Late last month, CBS touted that its month-old partnership with video-sharing site YouTube had yielded nearly 30 million views in the first month. But while YouTube viewers may be watching CBS clips to the tune of about 857,000 each day, only the two late-night talkers have generated a ratings rise during that same time. The “Late Show With David Letterman” grew viewers by 221,000, about 5 percent, while “The Late Late Show With Craig Ferguson” increased total viewers by 144,000, about 7.5 percent, compared to the month prior.

Clips from late-night shows play into the YouTube sweet spot-comedy or music video-better than a snippet of a crime drama, Mr. Adgate said. CBS also posted clips and promos on YouTube from “NCIS,” “CSI: Miami” and its Web preview of stories in the running for the “CBS Evening News.” Those three shows did not generate a noticeable rise.

CBS spokesman Dana McClintock said the network is encouraged by interest in its late-night fare posted on the Web.

NBC partnered with YouTube over the summer to promote “30 Rock,” “The Office” and “Heroes” in advance of their season premieres, and that timing makes it tougher to draw a causal connection between promotions and ratings. Still, both “Heroes” and “The Office” appeal to the Web-savvy demo, suggesting that their strong performances this season may bear some connection to online promotion, said John Miller, chief marketing officer at NBC Universal Television Group.

“Heroes” has been a ratings hit and “The Office” has stayed steady.

“How much was me and how much was me swimming in the stream and fanning the fire? I view myself as the guy just throwing on some gasoline on the fire that was burning and trying to keep it hot,” Mr. Miller said.

Last season, Fox promoted “24” and “American Idol” on MySpace. Ratings for both shows rose year over year, but assigning the increase to an online promotion is difficult because those shows have so much marketing around them and they typically rise each year, Fox said.

Ratings for “How I Met Your Mother” on Nov. 27: 3.5/9 in adults 18 to 49, a 3 percent rise above the season average; 3.3/9 in adults 18 to 34, a 14 percent rise above the season average; and 9.9 million total viewers, a 7 percent rise above the season average.