Early in the year, Google began addressing complaints that their search results had become polluted with poor quality links from so-called "content farms". The search giant rolled out an update to its search algorithm known internally as "Panda" at the end of February. Now Experian Hitwise, a web traffic research firm, has directly measured the impact of the change. Noted content farm Demand Media has taken a 40% traffic hit since the update happened.
The sites in question have been lambasted in the conventional blogosphere for being driven only by search hits and posting poor quality content. Using search engine optimization, these articles were able to reach the top of Google results and draw in users. Experian Hitwise used the downstream click-through of users that visited Google to evaluate the traffic lost to Demand Media. The 40% figure is just the average across all the Demand sites.
The eHow domain saw a 29% drop off. But one of Demand's smaller sites, Answerbag, is down over 80%. Stock in Demand Media has toppled 40% in the last few weeks. The company has had little to say about the issue, but we imagine they are not amused. Similar sites Mahalo and Associated Content are down 78% and 61% respectively.