According to the Google, Unatural & Artificial links are classified as below: Paid links:- Buying links from other sites which sells. Link exchange:- exchanging links between sites ( excessive ). Linking to or getting links from web spammers & Unrelated sites. Creating or Building Partner pages exclusively for the sake of cross linking between the pages to pass the page rank. Using automated programs to build links Excessive text ads which passes Page Rank Getting links from Low Quality Directory or Social Bookmarking Getting text links from article for unrelated keywords:- When we submit articles to the article directory or provided the article to guest bloggers with having our link as anchor to the several keywords which are not relavent to each other and if that passes Page Rank to the website which is linked, that will cause to loose ranking. ex: getting link to website from keywords " french vacation " and " cheap blankets " from the same artic...