Google says it has tweaked its results ranking algorithm to improve search quality, a move everyone interprets as a shot at content farms. Google says the tweak has affected 12% of its results, and takes pains to point out that, although it didn’t use the feedback from its recent Chrome extension that allows users to blacklist sites, the results were comparable. Eh? Search watchers say 12% is actually a pretty big change. Demand Media, the most visible of the content farms, says yes, its traffic has been affected, but not in a material way. Matthew Ingram and I analyze the risks and benefits across a broad variety of businesses that create low-cost, search-optimized content in this report.