Originally when webmasters learn the importance of back links they started looking for various sources to build links for their websites. Some people found this as a great opportunity to make money and started link farms and started selling links from their link farms. Thousands of links went out from these link farms and the value of the links from such link farms started reducing. Moreover, search engines also found this practice of obtaining back links from link farms a manipulative strategy and also it was noted that it did not really serve the search engines’ purpose. Search engines used back links as an important criterion of ranking and assessing the importance of websites