Twitter to allow advertising

Companies, including Best Buy, Virgin America, Starbucks and Bravo, said they would run ads, the Times said.

Here’s how it works: Best Buy, for example, will buy certain keywords and link their advertisements to them. When someone searches for that word, the company’s promoted message will show up at the top of the results, according to the Times.

The posts will say “promoted by Best Buy” or any other company, in small yellow type, the Times said.

Twitter started in 2007.

It has grown quickly in popularity, with celebrities such as Oprah Winfrey and Ashton Kutcher "tweeting" messages of 140 characters or less alongside everyday users. About 22 million people in the United States used Twitter.com last month, up from 524,000 visitors two years ago, according to comScore Inc.

Its founders used the “get people to use it first, figure out how to make money later,” business strategy.

Under the Promoted Tweets plan, companies will pay per thousand people who see promoted posts, according to the Times. Once Twitter figures what people do with those posts, then the company will start tweaking how it charges advertisers.

An ad won’t stay up if no one is looking at it, and the company won’t have to pay for it, either.

In fact, the ads apparently won't bring in much money during the experimental phase of Twitter's commercial push. Virgin America, one of the advertisers that Twitter invited to test the concept, isn't paying for its first burst of promotional messages, according to Porter Gail, the airline's vice president of marketing, told The Associated Press.

"I would expect that it would turn into a paid model in the future," Gail told The Associated Press. Twitter said Best Buy Co., Sony Pictures and Starbucks Corp. are among the other advertisers using Promoted Tweets.

Twitter will measure what is called resonance: nine factors that include the number of people who saw the post, the number of people who replied to it or passed it on to their followers, and the number of people who clicked on links, according to the Times.

If that’s not high enough, the ad goes away, and so do those ad dollars, the Times said.

Promoted Tweets eventually will show up in a users Twitter stream – something that Twitter knows is a risk. That won’t happen for a while, however, and the promoted posts are supposed to be specifically tied to that user’s interests, the Times said.