A German SEO tools company’s analysis shows that a new tweak of Google’s search algorithm has driven search results page-placement down for content farm Demand Media’s biggest site. Demand’s stock is being hammered today, even though the company says its traffic hasn’t been dramatically affected. (A CNET attempt to measure the algorithm change’s effects is unconvincing – its methodology seems pretty light to me.) Matthew Ingram points out that Demand will find creating higher quality content adds expenses to its low-cost model that we wrote about in this piece. Demand told me recently that it has been hiring editors and installing procedures to raise quality. We’ll have to wait for traffic data from the measurement companies (comScore, Nielsen, Hitwise) to see whether Demand has really been affected, and if its response works.