Web traffic analyst comScore is reporting that Yahoo's Buzz social news service has already overtaken Digg in unique visitors per month, even though the social news site is still only in beta.

Yahoo Buzz had an explosive first few months, showing that it could generate 90% of the traffic that three-year old Digg could in only a matter of weeks. Furthermore, users of Buzz have been found to be more likely to comment on Buzzed stories.

But the success behind Buzz is hardly surprising, as we noted when the service received an upgrade. Yahoo is a world-class property, and Buzz stories get a prominent place on the search engine's front page.