Search engines then began utilizing complex ranking algorithm, which were difficult for the webmasters to manipulate so as to provide web surfers with genuine results. The rank of the web page was calculated mathematically by functions using strength and quantity of the inbound links. The higher the rank of the page the more chances it had to be viewed by a person. Later algorithms were developed which considered various other on-page factors such as rank and off-page factors such as hyperlink. Since the webmasters couldn’t manipulate the page rank, they began exchanging, selling and buying links, which lead to link spamming and even creation of numerous sites dedicated for this purpose.