Buzz buttons have increasingly been popping up on third-party sites alongside other social bookmarks such as Digg, Sphere and Reddit. Yahoo says the service has drawn 5 million users to date.
Stories generating the most Buzz can make it to the Yahoo home page. For smaller publishers that land stories on Yahoo.com, the promotion can bring a server-busting surge in traffic. In the first two weeks testing Buzz earlier this year, Yahoo sent 16 million visitors to participating sites including those of The Huffington Post, Salon and Us Weekly.
Yahoo also exercises editorial control over which stories ultimately make the jump from Yahoo Buzz to its main page.--Mark Walsh