PR can impact your SEO and SEM, depending how you structure your content. Today, it’s used as the gold standard for measuring the quality of a web site or blog.
The history of PageRank (PR)
It was developed by Google founders Larry Page and Sergey Brin at Stanford. At the time that Page and Brin met, search engines typically linked to pages that had the highest keyword density, which meant people could game the system by repeating the same phrase over and over to attract higher search page results. PR is patented by Stanford, and the name PageRank comes from Larry Page.
What does PR accomplish?
It has become an accepted Standard that measures a web page’s importance using baseline values inherent to the software code of PR.
Page and Brin’s theory is that the most important pages on the Internet are the pages with the most links leading to them. PR thinks of links as votes, where a page linking to another page is casting a vote.
PR is one of many factors that determines where your web page appears in search result ranking, but if all other factors are equal,PR can have significant impact on your Google rankings.
What is the PR scale?
Every web site or blog is assigned a PR value and the scale is below: zero to ten. The comments are mine from observations over the years.
0 – You are NOT listed on Google, or you have been removed.
1 – Very poor. The only good part about a one is you are listed.
2 – Poor. The good news, you can improve.
3 – Average. Most sites are about a two or three.
4 – Above Average. You’re doing the right SEO and SEM.
5 – Excelling and moving in the right directions.
6 – Your are in the BIG results area now.
7 – You have even more traffic and links to your site now.
8, 9, 10 – Apple, Microsoft, LinkedIn, Facebook, Twitter, YELP, YouTube, Google+
NOTE: PR operates on a logarithmic scale. This means that the difference between a PR0 ranking and a PR1 ranking isn’t the same as the difference between a PR7 site and a PR8 site.
When you have too many links that are lower than you PR linking to you, your PR is effectively pulled down (reduced). Conversely, when you have links into your site from sites with PR higher than your PR, your PR will increase; the higher PR ratings pull your up.