Online messaging service Twitter is introducing advertising, allowing companies to pay to have their messages show up first in searches.

The feature introduced Tuesday is called Promoted Tweets. Twitter says Best Buy Co., Sony Pictures, Starbucks Corp. and Virgin America are some of the advertisers.

San Francisco-based Twitter has grown quickly in popularity, but hasn't had a real way to make money. The eventual introduction of advertising comes as no big surprise. Analysts have long speculated about when and how Twitter was going to start making money off its popular service.