I have just two more to show you on PageRank. The first is to say that we believe that PageRank is allocated logarithmically. That is to say that for every one page with a PageRank of 10 there would be 10 pages with a PageRank of 9, and a hundred with a PageRank of 8. This also means 10 trillion with a PageRank of 0. It is 10 times more difficult to go from PageRank 1 to 2 than it would be to go from page 0 to PageRank 1. PageRanks 1 -3 are not difficult to obtain but by the time getting up to 4 and 5 then these sites are significant and we are into the Wikipedia's and Google's of this world to achieve PageRanks 8 to 10.

Search engines are commercial companies. Their income depends on the number of searches they receive and searchers are influenced by the quality of the top positioned webpages, presented by the various search engines. Backlinks and PageRank, in particular, G-Factor-1 as provided by Keyword SEO Pro, have a significant role in positioning.

We know that Google looks at more than the sheer volume of votes cast or the number of links a page receives. Google also analyses the page that casts the votes. Votes cast by pages that are themselves important, weigh more heavily and help to make other pages important.

The authority or reputation of the linking page, almost certainly depends on its PageRank with the page with a PageRank of 8, carrying greater value in its votes than links from a page with a PageRank of 1 and a page with a PageRank of 0 probably has little if any value in a link but that page may in itself increase in PageRank in the future.

The number of links on the page is also of importance. We may consider that a page has a voting value of 100. If that page has one link only then that link will carry 100 votes. But if the page has 100 links then each vote cast would be worth just one.

We also need to consider the relevance of the linking page. If my 2womenshealth.com website could receive a link from the American College of Obstetricians and Gynaecologists, that would carry far greater value than a link from a local garage.

Search engines have means to detect when linking patterns are natural and when they are being artificially inflated. They can tell by the diversity of link sources such as links from related webpages and links from social networks. They can also tell by the timing of linking patterns. If a page suddenly acquires 100 links today, and then no more until four weeks time when it receives another 300 links, it would be apparent that those links are artificial and would almost certainly be discarded. It is apparent that scoring systems that evaluate off-page factors purely on numbers of links or of little value. PageRank, and in particular, G-Factor-1 is the best modality that we have to indicate how Google evaluates the importance of a page in terms of off-page optimisation.