Google Panda 4.0 has been officially rolled out today. In real, Panda update was designed to penalize the website having poor quality of content and ranked down them in search results. This algorithm always targets the website with low quality content so that Google can provide the best outcomes in the search results.
Panda 4.0, which Google and Matt Cutts confirmed bring into being rolling out yesterday, has certainly caused some waves in the search results. Though, the fact that Panda 4.0 is also hitting at the same time as a refresh of an algorithm targeting spammy probes like payday loans makes it a little bit more problematic for webmasters to sort through the loss.
Prior to Cutts approving via Twitter that Panda 4.0 hit, there had been plenty of rumor about a change with either Panda or Penguin, even though many found it hard to pin down exactly what the change was.