Here are some facts about page ranks that a webmaster should keep in mind. The sites do not have a page rank, pages have. PageRank to some level is link referral program. The page "A" ranks higher when it gets referred by another page "B", however just the number of referrals or links is not enough for a page to rank high. The rank of "B" site which refers user to site "A", is also important in determining the rank of site "A". To check the PR of a page, download Google toolbar or use Firefox plugin. PageRank is bit outdated Google technology. Today Google uses advanced algorithms in order to produce search results. Formula calculates many variables such: Keyword Usage Score, Domain Strength, Content Quality Score, User Data and Inbound Links. However, webmasters around the world still compete for good PageRank since it represents popularity of your page. PageRank is trademark of Google, but true patent owner of PageRank is Stanford University. Google has exclusive license rights to use PageRank. The cost of this right was 1.8 million shares of Google ($336 million in 2005).