The social-media site said it is introducing advertisements that let companies pay to have their messages appear in searches on Twitter's site. The move comes as Twitter faces more market pressures about how to convert its following of about 70 million users into profits.
Virgin America, Sony Pictures and Starbucks are among those advertisers initially involved. They are participating in something called Promoted Tweets, ads that run on top of search results on Twitter, much as sponsors can pay for listings atop rankings on search engines such as Google, Microsoft's Bing and Yahoo.
Twitter users are likely to see the ads when they search broadly for topics being tweeted about. The ads will look like tweets, with a disclaimer.