Google has in it’s algorithm a method that detects over-optimized websites. The detected websites are downranked in the Google search results. This over-optimization filter in Googles ranking algorithm is also called the “-950 penalty” because that is what may well happen to over-optimized web pages as they are downranked 950 positions.

Google’s anti-spam engineer Matt Cutts published a video in which he also mentions over-optimization as a reason for ranking problems. He says specifically that it’s more advantageous to not spend your time in the SEO forums but provide quality content that visitors are looking for and your rank will take care of itself.

The 950 Penalty–In The Google Algorithm

Matt Cutts video explains the way Google and will look at your site.