Therefore, a company who paid for inclusion within a search engine will still have its rankings determined by relevancy.
[3][4] Unlike the other major search engines, Google decided to avoid paid inclusion and, instead, pursue higher relevancy using AdSense as its revenue source.
[6] Aaron Wall of the popular SEO site SEOBook.com criticize Google's use of paid inclusion as a way to push almost all organic rankings below the fold.
The advantage of a paid inclusion search engine is that spam is reduced while relevancy improves.
[10] For this is only a guideline and not a law, companies with search algorithms such as Nextag and Google are not legally bound to follow it.