Before April 2012, keyword ranking was easy to index by search engines with Google PANDA updates. This algorithm was designed only to reduce rankings for low quality sites which copy the content from other websites. Hence many Black Hat SEO Guys made 1000 of backlinks anywhere to promote their websites and keywords without justifying the relevant content and Google’s guidelines.
After Google PENGUIN Updates, the value of all these Spam links have been vanished and the both sites have lost the rank of their pages and keywords.
I use Link assistant to find out the competition links through competitor's websites for which they are on the top position on major search engines. I read all guidelines and post the content with backlinks carefully. My link building technology is 100% ethical, relevant and guaranteed. I am aware of Google new penalization rules and my Keywords are still on the top after Google Penguin Updates.