To Protect Advertising, Twitter Walls Off Tweets

摘要

In April, Twitter began selling "promoted tweets," little ads among those ubiquitous, 140-character messages. Brands-including Starbucks and Best Buy-post ads that appear if users search for certain terms on the site. If someone enters "Red Bull" in the search box on Twitter.com, a paid tweet from the beverage maker may appear rnamong that person's messages from other users. The advertising is crucial to the four-year-old site, which attracted 110 million users before it had fully articulated a business model.