Paying a celebrity thousands of dollars to promote your company in 140 characters or fewer may seem crazy. But a growing number of businesses are setting aside marketing dollars to do just that. Best Buy recently tapped reality star Kim Kardashian to tweet about its cell phones, for instance, and Microsoft hired entertainment mogul Diddy to tout its mobile tagging service, Microsoft Tag, to his legion of Twitter followers. Any company can snag an endorsement from a star using services that connect advertisers with tweeters—for a price, of course.

The Company: CampusLive, a Boston-based website that lets college students earn rewards from sponsors by playing online games

The Goal: Encourage more college students to register on the site

The Execution: Figuring an endorsement from a star would grab the attention of college kids, CampusLive founder Boris Revsin started exploring the idea of sponsored tweets this summer. He held a focus group with students to find out which celebrities seemed most influential, and Lindsay Lohan's name kept coming up. Revsin checked the starlet's Klout score—a ranking of social-media influence—and was impressed to see she scored a 78 out of a possible 100. Some quick online research revealed that she worked with SponsoredTweets, a Web-based platform that connects advertisers with celebrities and offers online analytic tools for gauging the success of campaigns. Revsin logged on to the SponsoredTweets website and submitted the tweet he wanted Lohan to post. The service contacted the starlet and, about three weeks later, she agreed to publish a slightly tweaked version of the tweet for $3,530. To hedge his bets, Revsin browsed SponsoredTweets's listings and requested a second tweet from rapper Jim Jones, who charged $1,950. Revsin paid for the tweets on the site and requested they be published on the same day in August.

The Result: Within a day, some 4,500 people had visited CampusLive by clicking on a link to the site in Lohan's tweet ("These challenges for college kids on #CampusLive are SO addicting! Have u checked it out?").That number was lower than Revsin had hoped, but he was impressed with the conversion rate: Five hundred of those visitors went on to register on Campus-Live, and many of them are now regulars. Jones's tweet ("College #Vampires brought to you by the #CampusLIVE payin homage to da legends check it.") was much less successful. Only 1,000 people clicked on the link in his tweet to visit CampusLive, and 50 of them signed up. Revsin attributed the disappointing results to the fact that Jones has less name recognition than Lohan, who is also 10 years younger. Lohan's message was also more enthusiastic, he adds. Lohan's rate, by the way, has fallen since CampusLive hired her.

Revsin has decided not to feature Jones in future campaigns but plans to purchase more tweets from Lohan. Is he worried about associating his company with a controversial star? No. "People still follow her and do what she does," he says. "It's like that strange thing, where you can't stop looking."

The Price Tag: $5,480

Expert Tips

Avoid overexposure
As celebrity tweeting becomes more popular, its effectiveness might dwindle, warns Susan Etlinger, an analyst at the Altimeter Group, a consulting firm in San Mateo, California. Before hiring a star, check his or her Twitter stream to see if it's overflowing with endorsements for other brands.

Choose Wisely
Hiring a controversial star to send a few tweets is likely to generate buzz, Etlinger says. "If your only goal is to drive people to your website, it doesn't matter if they're famous or notorious." However, she warns, your brand could be tarnished if you stick with the person consistently.

Tweeting With the Stars

How much will you shell out for a celebrity endorsement? Below is a sampling of stars for hire on the SponsoredTweets platform.

  • Fee per tweet
  • Number of followers

Lindsay Lohan
$2,353
2,472,484

Frankie Muniz
$208
119,789

Jose Canseco
$3,900
400,475

Soleil Moon Frye
$5,850
1,449,763

Lance Bass
$134.33
104,288

Mike Tyson
$3,250
851,168

JWoww
$2,353
1,549,310

Tyrese
$4,550
1,595,225

Khloé Kardashian
$8,235.50
2,856,036

Source: SponsoredTweets

Check this out for more social media strategies.