I have done on page optimization and off page optimization for http://www.consumerhealthanswers.com . In off-page optimization, blog posting, article directory submission, document sharing sites and also done SMO Social Media Optimization i.e. facebook, twitter, stumbleupon, pinterest. Our content is pure not duplicate and i am not doing pure link building for this site. But after penguin update 2.0, my project ranking is drop and still not stable. For e.g. my keywords "Amberen" & "Amberen Reviews" is drops for this link http://www.consumerhealthanswers.com/amberen-reviewed.html why.
Even good sites affected because of this Penguin2.0. This Penguin2.0 hates deleted or 404 links we created. All you have to do is find and delete or create new links. Even I sufferred the slump but surviving on the first page.