Tech critic Andy Beard of the blog Collective Thoughts noted that Alexa added a penalty for websites that had a disproportionate number of users who had the Alexa toolbar installed on their web browsers.
The Alexa toolbar provides web surfers with several different tools while also collecting information for Alexa's web rankings.
But Beard said he saw evidence emerging of another penalty being added to Alexa's rankings algorithm – this one aimed at social bookmarking websites like Digg.com, Reddit.com and others.
Alexa has not formally announced any further changes to their ranking system, and representatives for the company were not available for comment as of post time.
Social bookmarking websites let users submit interesting links and vote on how much they like them. Popular submissions advance to the front page of these sites, where they can attract tens of thousands of hits to a site.
According to Beard, Alexa has slowly started to downplay the importance of traffic that comes in from social bookmarking websites. Beard added that he generally agrees with the decision.
"This is something potentially valuable to advertisers, as huge traffic spikes are possible from the largest social sites that can lead to an imbalance in their trend data, especially for the most recent three-month period that appears in their toolbar by default," he said.
Ryan Caldwell of the tech blog Performancing.com agreed with the hypothesis that Alexa is discounting the importance of social bookmarking traffic.
Caldwell also agreed that social bookmarking traffic doesn't convert well.
"Now why would Alexa do this? I think the answer is simple. Alexa wants to be a tool used by advertisers," he said. "And advertisers know that social media traffic is worth much, much, much, much, much, much, much less than search and repeat visitor traffic."
Online guru Brandon "Fight the Patent" told XBIZ that although the adult industry hasn't generated a really popular social bookmarking alternative yet, he wasn't so sure that the traffic was worthless.
"My take is that these sites get eyeballs," he said. "And those eyeballs have the opportunity to view and click on the graphical advertisements around them."
Adult social bookmarking websites include X-Digg.com and SmutPost.com. SocialPorn.com was defunct as of this writing.
Mainstream social bookmarking website Reddit.com has dedicated an entire section to links that are not safe for work. The popular link site also recently offered its platform to the open-source community, and an adults-only clone, Fuddit.com, has already popped up. To download the Reddit source code, visit Reddit.com.
