I was ranking #2 for a very very low competition term (only 164,000 results in Google and the results are super weak). The #1 site is an authority site with tons of natural backlinks, not going to pass it, but I was happy with #2. After Penguin update my site fell off the map. Site has unique articles on it (written by me, no rewriting), a unique site, and no ads on it. I'm not in top 100 results anymore for this keyword. What is funny is that in the top 100 results, there are blog posts, comments, etc... that was done as part of my SEO efforts which all link to my site. I probably have 35 of the top 100 results which are pages that has my SEO work on it with the backlink to my site. My site is #2 in Bing and Yahoo. F Google. What a joke.