Earlier this week, Google rolled out Panda 4.0 and Pay Day 2.0. These updates to the search algorithm were touted as being designed to further reduce the ranking of low-quality and spammy content. According to analysis by Searchmetrics, Panda and Pay Day did just this, with websites that offer undifferentiated content suffering in terms of overall ranking.
However, Panda did not just punish websites: various major websites actually increased their rank in Google Search as a result of the change in algorithm. From the study: expand full story