Spam is a collection of all of the unwanted content on the internet, such as unsolicited advertisements sent in the form of emails. Although strict laws have been put in place against spamming, such as the CAN-SPAM act, spammers continue to exploit such laws and carry out their activities. Spam acts as nothing but a deterrent for search engines, working against letting them deliver relevant or quality content. Some of the prime examples of spam are unnecessary doorway pages designed for no other purpose than to please search engines but serving no purpose whatsoever to human visitors or repeating the same search terms again and again on a page, in the hopes of getting a higher search result ranking.