Most of the people are appreciating Google about their new change in algorithm which was part of their fight against scam. The sites which have copied content or non-unique content are penalized by the Google. These sites includes article directories, Question Answer communities and forums. We know that most of us make backlinks from these platforms so as I have made and now all backlinks from these sites does not carry any worth so my rankings of several keywords has been dropped to 4 to 7 places and this situation has made me really worried I succeeded to rank my assigned client on the page 1 after very tough competition. But all my hard work results in nothing now. I think now we should rely less on the SEM and focus more on SMM, because Google is very unpredictable. You can read more details about this algo change in Mass Cutts blog.