Google announced that it has rolled out a new algorithm change directed at low quality content. While the company did not mention content farms specifically, it is understood that the change is aimed at sites like eHow.com that generate endless streams of content with some of it being of questionable value (like: "How to Buy a Flattering Speedo").
Google claims that the change will affect 11.8 percent of US queries which is a significant number as most algorithm changes involve 4 percent of searches or less. In the company's official blog post, they also correlated the algorithm change with sites included in user data gathered from the new Personal Blocklist extension for Chrome.
"If you take the top several dozen or so most-blocked domains from the Chrome extension, then this algorithmic change addresses 84% of them, which is strong independent confirmation of the user benefits."
Demand Media, whose online properties have been under scrutiny since Google announced its war on content farms, responded by saying that with the change, some content saw improvement while some pages dropped but the overall net effect did not hurt their business. In their most recent call with investors following their IPO quiet period, the company said that in addition to search, they receive millions of visitors from social media, referring sites, direct visits and other search engines and that even with Google's updates, the company was still growing.
Google has recently implemented high profile algorithm adjustments in an effort to combat low quality content. After a New York Times article about an eye-wear company encouraging negative reviews to boost their rankings, Google introduced sentiment analysis for web reviews and recently launched an update aimed at sites that scrape content and rank over the original publisher.