Google Page Rank

Page Rank or PR is a publicly known formula that Google uses to help build search engine result pages.

The Formula

PR(A) = (1-d) + d(PR(t1)/C(t1) + ... + PR(tn)/C(tn))

Or more simply..

A page's PageRank = 0.15 + 0.85 * (a "share" of the PageRank of every page that links to it)

PR or Page Rank Explained

Page Rank is one of many factors that contribute to a website's position within a search result page. Think of each page within any website as having 1 vote.   Every time it links to a page or site it casts a share of it's total vote to that linked page or site. If you have 1 link linking to 1 external page that external page will have 1 vote cast for it.  However if that same page now links out to 2 pages, it can only cast a 50% vote for each, as the number of links are increased the weight of each vote is decreased.  The total some of all votes must equal 1.

For this reason more pages and more links are essential to any SEO Campaign