Last Thursday, Google launched a new tweak to their search algorithm. It was targeted at content farms, which many consider to be spammy sites whose content are created solely to attract search engine traffic for specific keywords.
I do notice more and more of these sites on Google’s search results. For me, the main offender is ezinearticles.com. Most of the articles I get from there are completely useless. They’re just keywords being repeated over and over again with a bunch of fillers. I can see why Google wants to push those sites further down their search rankings.