Many wonder what is the Page Rank (PR ™) and what role it has in relationship with the search engine optimization (SEO). PageRank is a value between 0 and 10 assigned by the Google algorithm, which quantifies link popularity and trust among other factors.
Formula developed by Google to determine a web pages pagerank:
PR(A) = (1-d) + d (PR(T1)/C(T1) + … + PR(Tn)/C(Tn))
PR(A) is the PageRank of a page A
PR(T1) is the PageRank of a page T1
C(T1) is the number of outgoing links from the page T1
d is a damping factor in the range 0 < d < 1, usually set to 0.85
It also means that if a page has no links to it (no Backlinks) will receive a low PR of 0.15 (1 - 0.85).
A sure way to gain Page Rank is to submit your site to web directories and make link exchange with websites from the same niche.