As a user though, I can't understand why anyone goes here. Whenever, I stop by the only stories I see are either hard core tech geek stories, spam (cleverly disguised as stories which are then "voted up" by the interested parties - i.e. they game the system) and/or fringe stories that perhaps are amusing to some but are of no relevance to me. So content wise, I don't get it.
Design wise, I don't get it either. And this is coming from somebody who loves the whole "ugly but functional" design. I use an IBM Think Pad as my machine. When I go to Digg, the top 50% of the screen is their mast head, ads and a tab bar - i.e. zero content. This leaves room for only 3 of the aforementioned "stories" for me to see without scrolling. On top of that, with all the links near every story and the clutter on the right side of the page, I can't focus on a single thing.
So I don't dig Digg. And to be honest, I don't think others do either. As the article notes, they saw 2.2 million (ComScore) uniques last month, which is respectable. But hardly huge. Given that the users they do have are vocal and/ or self interested, they get just about the best PR of any company out there, they have managed to convince lots of news papers to put their viral "digg this" button next to their stories, and they're well indexed by the search engines, it's actually kind of small.
For reference, Digg has been live for about 1.5 years. Without the benefit of Business Week cover stories and viral plugs across the news world, Topix had a much larger audience than that after our first 1.5 years of existence. (We're up to 10mm per month now).
So again, I don't get Digg. But what I really don't get is that, why does everyone else want to copy them. Netscape news tried. Look what it did to their traffic. Now MySpace is getting into the act. Will it succeed - who knows. Perhaps it is a better "fit" for their brand. Judging from the screen shots, the design looks a lot better.
In any event, I quoted Bob Lefsetz a couple of entries ago when he said "the mainstream is a sideshow." I love that quote. Right now, Digg and, thus far, its clones are the darlings of the mainstream press, but a sideshow for the rest of us. We'll see if it stays that way.