Twitter has reshaped how people shop, vote and start revolutions and now it's changing the business of celebrity endorsements.
Social media marketer Izea says Singer Ray J got about $2,300 to urge his 600,000-plus Twitter followers to see the horror movie "Saw 3D." And reality TV star Khloe Kardashian was paid about $8,000 to tweet about how Old Navy jeans make the Kardashian derriere look "scary good."
Of course, anything on Twitter is short-lived and reaches only a small, self-selecting audience.
Research firm eMarketer estimates that only 11 percent of U.S. adult Internet users are on the micro-blogging site. And even though some celebs have faithful groups of followers, it can be hard to measure whether their tweets get people to spend.
Still, paying a celeb to tweet is much cheaper than a traditional advertising campaign.