Google webspam guru Matt Cutts explained the rationale behind Penguin in a post on the Google Webmaster Central blog. He noted that We see all sorts of webspam techniques every day, from keyword stuffing to link schemes that attempt to propel sites higher in rankings. Penguin represents another improvement in our efforts to reduce webspam and promote high quality content. It’s supposed to decrease the rankings of sites that violate Google’s terms of service. Cutts gave two examples of websites whose ranks he expected to see drop after Penguin. One displayed egregious keyword stuffing. The …