Tweet It Maybe

For decades, the song of the summer would emerge each year following a pattern as predictable as the beach tides.

Pop radio would get it rolling before school let out, and soon the song - inevitably one with a big, playful beat and an irresistible hook - would blare from car stereos everywhere. Then came prom singalongs as the song finally became ubiquitous around the Fourth of July. In 1987, it was Whitney Houston's “I Wanna Dance With Somebody.” In 2003, Beyoncé's “Crazy in Love.”

But the success of this summer's hit, Carly Rae Jepsen's cheerfully flirty “Call Me Maybe,” shows how much the hitmaking machine, as well as the music industry itself, has been upended by social media.

Only a year ago, the charts were dominated by stars who had come out of the old machine of radio and major-label promotion: Katy Perry, Rihanna, Adele, Maroon 5. This year's biggest hits - “Call Me Maybe,” Gotye's “Somebody That I Used to Know” and Fun.'s “We Are Young” - started in left field and were helped along by YouTube and Twitter before coming to the mainstream media.

A tribute version even brought the song to the attention of President Obama. In an interview with KOB-FM, a New Mexico radio station, he said: “I have to admit, I've never actually heard the original version of the song. I saw this version where they spliced up me from a whole bunch of different speeches that I made. They kind of mashed together an Obama version of it.”

Nearly two-thirds of teenagers listen to music on YouTube, more than any other medium, Nielsen said last week. Ms. Jepsen said in a recent interview that “the viral videos are what's been the driving force for this. It was insane to see that the music could spread that far because of the Internet. It's a cool thing. It changes the game completely.”

YouTube, Twitter and Facebook are now record labels' textbook tools for starting a marketing campaign, and if the numbers there are big enough, they can be used in pitches to radio and television programmers.

To introduce Cher Lloyd, a 19-year-old singer who was on “The X Factor” in Britain, Epic Records set up a “queen” fan to beat the drum on Twitter, and coached Ms. Lloyd on what to mention online - a TV appearance, for example, or the Twitter handles for radio D.J.'s.

“In this day and age, artist development is about how do you turn 10 Facebook likes into 100, into 1,000,” said Scott Seviour, Epic's senior vice president for marketing.

The song catapulted Ms. Jepsen, apple-cheeked and giggly at 26, from obscurity to worldwide fame. Five years ago she placed third on “Canadian Idol,” and last fall she released “Call Me Maybe” in Canada to preview her second album. By the Christmas holiday it was a minor hit in Canada, when Mr. Bieber heard it.

“It's supposed to be a fun song,” Ms. Jepsen said. “Not to take yourself too seriously, to put you in a good mood.”

Mr. Bieber's role in popularizing the song reflects the importance of both social media and old-fashioned celebrity promotion. On Dec. 30, 2011, he told his 15 million Twitter followers that “Call Me Maybe” was “possibly the catchiest song I've ever heard lol.” Shortly thereafter, he and Mr. Braun signed Ms. Jepsen to their label in the United States, Schoolboy, which is affiliated with Interscope Records and the Universal Music Group.

To exploit the success of the single, which has sold eight million downloads around the world, Ms. Jepsen delayed the release of her album. Called “Kiss,” it will now be released next month, when she will also hit the road as an opening act for Mr. Bieber.

The song's trajectory also demonstrates the continuing power of radio, which record executives say is still essential to turn any song - no matter how much online buzz it has - into a genuine smash.

In March and April, when “Call Me Maybe” was getting tens of millions of views on YouTube, it still had relatively low radio play - fewer than 5,000 spins a week on Top 40 stations in the United States, according to Nielsen. It hit No. 1 on iTunes on May 27, but took almost a month to reach No. 1 on Billboard's singles chart, which counts sales as well as airplay and streaming services. By then it had about 20,000 spins a week on multiple radio formats.

“There's not a million-seller out there that doesn't have radio play,” said Jay Frank, chief executive of the label DigSin. “But its first million generally doesn't come from radio.”

“Call Me Maybe” is a watershed case for the use of social media as a marketing tool, but the song's success will be difficult to replicate - even for Ms. Jepsen as she prepares to release her album. No matter how hard a record company might push, popularity online depends on the enthusiasm of individual fans.

The marketers behind Ms. Jepsen have worked to organize it to some degree, through tools like a Tumblr blog collecting fan tribute videos. But Jonathan Simkin, her manager, said that trying to control the energy wasn't the point.

“That's part of the beauty of how this has grown,” Mr. Simkin said. “This is just people who the song struck. I don't want to harness it or limit it. I just want to pinch myself and say, ‘Thank God the song affects people this way.' ”

Ms. Jepsen said she was not worrying about trying to line up another megahit, because that kind of success is never predictable.

“I never know what is a hit and what isn't a hit,” she said. “I just write what feels natural and good. At end of the day you just release it and hope for the best.”