Most of you will be aware of the infamous Digg auto bury algorithm by now, for the uninitiated it is a system that prevents all stories from certain blacklisted domains from ever becoming popular. The first time I became aware of the algorithm was in late March 2007 when stories from a certain blog of mine were continually being buried for no reason, sometimes identical stories from lesser blogs were made popular the next day.
Before auto bury came into play Digg used to simply ban urls they didn’t want reaching the homepage. Late last February Digg decided that it would be better to let people submit stories from the banned domains again but made sure they were all added to the auto bury blacklist.
In the past the key characteristic of a domain that was auto buried as opposed to buried by real users was that it was buried after only 2 or 3 Diggs. Something that would be highly unlikely to occur purely through natural burying because not enough users would see the content.
To quote a Graywolf article from March 2007:
Certain domains are flagged to be automatically buried and removed from the normal voting system with as little as one vote and within few as few hours of getting in the queue.
This characteristic meant it was easy to detect domains on auto bury – you just did a search for the url with and without the “Include Buried Stories” checkbox ticked. If all your posts were being buried even those with only a couple of Diggs then you were on the auto bury list.
The Change
At the end of November 2007, just before Digg carried out a major redesign, the auto bury algorithm become more sophisticated. Gone was the mass burying of content with only one or two Diggs – content started only being buried when it gained enough Diggs to have a chance at becoming popular.
New domains such as Copyblogger were quietly added to the auto bury blacklist but because only the stories with a chance of becoming popular were being buried not many people noticed (everybody noticed Copyblogger after Brian pointed it out). After all, not every story can hit the front page so it’s common to see one fall just short.
Now a search for a domain on auto bury reveals lots of posts that haven’t been buried whereas before November every single story would have been buried. The only stories that are being buried under the new algorithm are ones that would probably have gone on to become popular.
So, if you have been struggling to get your domain on the front page of Digg since the end of November, now you know why.
The evidence
To highlight the changes that have been made I will use johnchow.com as an example, it’s well known that John is on the auto bury list and he has a following of fans who still submit content to Digg so there are lots of stories to look at. I have tested this with a lot of domains on the auto bury list and all display the same characteristics.
In the first image we can see that there are no non buried stories between 43 days and 156 days old.
In the second image we can see that in fact there are loads of stories between 43 and 156 days old but they were all buried, even those with only a couple of Diggs. This was the old auto bury algorithm in action
The next image shows how the new algorithm is behaving, stories within the last 10 days have not been buried by the auto bury algorithm.
Finally we can see that the only story to be auto buried since the end of November is a good story that had the potential to become popular.
Patrick Altoft is Director of Search at Leeds based digital & SEO agency Branded3. Patrick also runs Blogstorm.You can get our blog posts delivered for free by email every day - simply add your email address to the box below or alternatively grab the RSS feed.
{ 10 comments… read them below or add one }
Just a small question: how do you know a story is buried?
Find me on Twitter
If the story is no longer in the “Upcoming” queue of the section you submitted it then it has been buried.
More comments from Patrick AltoftThanks Patrick. Who buries the story? I mean, there are people who’s bury button carries a lot more weight than our normal mortals, right?
Find me on Twitter
Anybody can bury a story, I guess trusted users buries have more weight than normal users just the same as some Diggs are better than others.
If the site is on the auto bury list it is because of the decision of the Digg management rather than the users.
More comments from Patrick AltoftSorry rookie question probably. How do you check if a story was auto-buried after that amount of time has passed?
Find me on Twitter
In the past if a lot of your stories were buried on less than 5 votes it was fair to assume you were on auto bury. Now you need to keep an eye on each story and see how many hours it took to be buried before you can guess at whether it was an auto bury or manual.
More comments from Patrick AltoftWhen it comes to domains that are being auto-buried though, it doesn’t take any real users to bury them, it’s an automated system.
Brother, you stole my thunder. I’ve been talking to lots of people about this for a couple of weeks, gathering evidence, trying to break down the algo. I’m glad it’s out there now, and I hope to add more to it soon.
My blog had 8 of the first 14 submissions hit the FP. Since then, the last 15 have been buried. I started tracking them closely 8 submissions ago and noticed that they all were buried between 20-26 diggs. Sometimes submitted at night, in the morning, any time. Always by different people.
The clincher for me was when MrBabyMan submitted one that was buried at 20 Diggs 42 minutes after being submitted.
Great article, btw!
I think you might be right on these assumptions. I tracked a similar patter on the blogs that I watch closely.
Digg is just trying to use more sophisticated means to mask their censorship. Sad.
I have recently discovered that I have been subjected to this too. 14 consecutive submissions have all been removed from upcoming at 20-25 diggs.
They are the work of various authors and have been submitted by myself and others. All have received nothing but positive feedback. The only common link is the URL.
I started a discussion on this which has caused quite a stir.
http://howtowritefortheweb.blogspot.com/2008/02/my-war-with-diggcom.html
{ 2 trackbacks }
Leave a Comment (registration is optional)