How do Digg, Reddit, Netscape etc. Rank News Stories?

I just came across an excellent post by our neighbor just South of the 49th parallel. Basically there has been a lot of chatter recently about Digg, and other social network news websites. Let's ignore all the "good vs. bad" editor talk and manipulation and take a brief look at Rand's post from a purely algorithm perspective.

For those of you not familiar with Digg and the like. Let me explain why the SEO community cares so much. Basically these sites have a couple of major benefits.

1. They can drive thousands of visitors and generate excellent industry buzz (if your story gets promoted properly) – short term benefit.
2. They can create hundreds of quality back links which will help your site rank organically – long term benefit.

Lately there have been plenty of posts about how to write a good Digg story, so lets focus on the math.

Basically stories get ranked based on the following algorithmic criteria.

• Number of votes over time
• Domain of link
• Profile of submitter
• Profiles of voters
• Timing of submission
• Similarity to other links (duplicate)
• Source of votes
• Manual review as it hits the homepage
• Number of comments
• Number of views
• Down votes
• Source of Votes

Rand has gone in to more detail in his blog – read his full post here. I felt that this information should also be posted here as there has been a lot of discussion inside our company about Digg and their competitors, so I thought posting this might help clarify how Digg works.