Facebook, owner of the world's largest social-networking site, said its advertisers have more than quadrupled since the start of 2009 as marketers aim to get their products before a growing global audience.
Facebook says it doubled the number of salespeople last year from 2008. The company didn't disclose the numberof advertisers or salespeople.
Companies are boosting ad spending after a lull during the recession to reach consumers who spend long stretches on the internet.
Facebook, which has more than 500 million users, counts Procter & Gamble and Virgin among its customers.
It is relying on ads to maintain sales growth and lay the groundwork for a possible initial public offering.
"We're very well positioned as people come out of this current economic situation," Mike Murphy, vice-president of global sales, said.
Facebook sells ads that are placed on the home pages of users, where the latest comments, pictures and links from their friends are posted.
The ads also show up next to profile pages, which may include a person's information such as gender or birth date.
Adidas has used Facebook to promote its youth-focused Originals label, said Chris Barbour, who leads global digital marketing for the company's Sport Style unit.
The company ran ads this year to drive more users to its Originals page on Facebook, which features new products and user discussions.
Three times as many people signed up to be "fans" of the page during the campaign, compared with the typical rate, Barbour said.
Facebook ran 176 billion display ads in the US in the first quarter, up from 70.7 billion a year earlier, says research firm ComScore.
