How is it compared to other sites like Digg? And which would you say was the best of them all, from a marketing perspective?
The similarities between Yahoo Buzz and Digg are obvious, although Yahoo Buzz takes some ideas from memetrackers such as Techmeme. By giving users (those who have signed in with their Yahoo ID) the ability to vote for stories, but at the same time calculating a story’s popularity based on searches, emails and other factors, Yahoo is trying to deliver the best of both worlds.
Like almost everything Yahoo! does, this is another failure they've come up on. Think of what they did to Altavista, Hotbot and such, and you can see the problem they have. Yahoo has a hard time putting anything long-term out there that has a profit structure beyond archaic ad formulas. Buzz is another failure and doesn't live up to Digg even on the most minor levels. IMO, Yahoo can be a great company but it's dragged down by mismanagement, misguided direction, and bad leadership.