Hi there, I just came upon an article from very interesting value. They analyzed 20 penguin winners and 20 losers with a total link amount from 80K backlinks from various sources. The company found some clear speaking numbers about which link types work and which are hurting your sites. The percentages show how much of that link type the analyzed penguin winners and losers have built. Here are the very interesting results: Authority Links Note: Ment are not some "HQ Web2.0s", ment are real Authority sites like elle.com or others. Winner Sites: 9% Looser Sites 0,9% Recommended: YES - Grade:1 (A+) Forums Winner Sites: 34% Looser: Sites: 9% Recommended: YES - Grade:2 (B) Blogs Winner Sites: 27% Looser Sites 10% Recommended: YES - Grade:2 (B) Yellow Pages Winner Sites: 2,1% Looser Sites: 1,5% Recommended: YES, why not - Grade:3 (C) Q&A Sites Winner Sites: 1,1% Looser Sites: 0,9% Recommended: YES, why not - Grade:3 (C) Press Release Sites Winner Sites: 4% Looser Sites: 8% Recommended: YES, but only a few! - Grade:4 (D) Social Bookmarks Winner Sites: 14% Looser Sites: 32% Recommended: YES, but only very very handpicked - Grade:5 (E) Directories Winner Sites: 8% Looser Sites: 22% Recommended: YES, but only very very handpicked - Grade:5 (E) Article Sites Winner Sites: 0,4% Looser Sites 16% Recommended: NO, never in my life - Grade:6 (D) Shocking impressive (red are the ones that used article links and lost rankings): The results have clearly shown that almost ALL penguin winners (higher rankings after penguin) have no links from article directories and almost all that have had a loss in rankings. You can read the whole article here http://www.libako.de/linkaufbau-studie-9-linkarten Please use google translate, if something is not clear, dont hestitate to ask me.