Running through SEOmoz's Indextools stats this month, Matt & I noted that Digg has sent considerably less traffic the last two times SEOmoz has been on the site than ever before (starting with our first "Dugg" post back in January 2006). On average, we see between 12-20,000 unique visits from making the Digg home page, sometimes considerably more (up to 30,000 at times). Below are some illustrative examples:

In February of this year, Matt wrote 3 posts that made Digg's home page:

The total for all Digg.com referrals was 68,000 in February. Now look at March, when SEOmoz had two articles hit the Digg home page:

In March, our total traffic from Digg was 34,000 visits, which pales in comparison to February, but still averages more than 15,000 visits per "dugg" post. April was a slow content month (for Matt, anyway, who seems highly attuned to what the Diggers want), but in May, we once again had 2 front-page Digg posts.

Total Digg traffic from May - 18,000; not even 10,000 visitors per "dugg" post. This suggests a pattern, but it's wise to consider all the alternatives before making a snap judgement.

• May isn't over yet - maybe we'll get a hug spike? OK, not likely, as most Digg traffic is very temporal and lasts only 2-3 days at the most.
• Maybe the articles in May made the homepage at bad times? Nope. The Web 2.0 article was on the homepage throughout a Wednesday morning and the 17 Rules post made popular around 11am on a Monday - prime Digg traffic hours.
• Perhaps Digg's traffic is using the RSS feed? Nope. Digg only shows the Digg URLs in the RSS feed, so users are forced to click-through to get the actual URL.
• Could those articles be less interesting to Diggers? Possibly... But, they don't have considerably fewer "Diggs" than our other posts (though a pair of Matt's had a LOT of votes). This would be the most likely alternate explanation.

Far be it from me to post information like this without checking on stats from others. According to my unnamed, but "on-Digg-all-the-time" sources from around the SEO world, Digg has also been sending them far less traffic than previous efforts.

My best guess is that the HD-DVD fiasco had a negative impact on Digg's regular readers. As noted in this Reddit thread, a gaggle of some size moved to that site, while some other posts suggest that general site abandonment over the issue was rampant. This doesn't put any kind of nail in the coffin, but it's more evidence that Digg has lost some of its traffic.

p.s. Digging more into historical Digg traffic - you can see that back in Jan. of 2006, we had 22,000+ visits from a Digg. Here's a post from June 2006 showing 16K visits in the first 9 hours. Barry also pointed out that a late afternoon Digg sent him 17K+ visits in February.