Twitter announced a feature called Promoted Tweets on Tuesday, allowing companies to pay to have their Twitter posts display at the top of searches on the site.
Twitter says its advertisers include Best Buy, Sony Pictures, Starbucks and Virgin America.
The Twitter microblogging service started in 2006 and has grown quickly, but has lacked a business model to make it profitable.
Twitter has partnered with Google and Microsoft's Bing to make its posts available to those search engines. The dollar value of those deals hasn't been released.
In a post on the Twitter blog, co-founder Biz Stone said the promoted tweets will be shown in search results, similar to the sponsored search results in Google, Bing and Yahoo.
Twitter users will see the ads when they search for topics being talked about on the service.
Stone said the program will later expand so that Promoted Tweets would appear in Twitter clients and other partner services.
Stone said the feature will measure if the sponsored tweets are "resonating" with Twitter users based on replies and forwards of the ad. If they fail to catch on, "the Promoted Tweet will disappear," he wrote.