Notice some unusual changes with your traffic these past few weeks? Expect so since Google Penguin is still rolling out and is now on its 45th day. This is one significant update since the version 2.0 last year but the precise toll on the total percentage of queries is still unclear.
This filter was designed against spammy sites in violation of Google guidelines about link-building. This filter was introduced in 2012, and now the new and improved Penguin 3.0 is said to be more efficient.
October 17, 2014, when Penguin 3.0 was first launched by Google. The roll outs and changes are still unclear, and it is reported to affect only about one percent of queries.