Most of us are unaware of the fact that Google toolbar Page Rank (PR) varies from Google actual (internal) Page Rank. Within Google's actual databases, each of your pages is stored and does have some form of numerical Page Rank calculated value. This is quite likely to differ from the toolbar page rank. It seems to be confusing as most of us refer to the toolbar for the relevancy of the page but in fact the actual Page Rank values are some decimal numbers such as 3.831 which might be shown as PR 4/10 or PR 3/10 on the toolbar scale. The Toolbar Page Rank value only indicates that a page is in a certain range of the overall scale. One PR=5 page could be just above the PR=5 division and another PR=5 page could be just below the PR=6 division, which is a huge Difference.

Page Rank is one of the factors that Google considers in determining the importance or relevancy of a page. Google calculates the page's importance from the votes (links votes) cast for it. It says that when one page links to other page, it is casting a vote for the other page. The more link votes that are cast for a page, the more important the page must be.  Page rank just not only relies on the quantity of link pointing to a page instead it relies on the quality and relevancy of those links. Link Popularity and Link reputation are the two important terms which are generally associated with the link votes.

According to Sergey Brin and Lawrence (Larry) Page, Co-founders of Google, the PR of a web page is calculated using this formula:

PR = (1-d) + d (PR(T1)/C(T1) + ... + PR(Tn)/C(Tn))

Where:

PR is the Page Rank of page A,

PR (Ti) is the Page Rank of pages Ti which link to page A,

C (Ti) is the number of outbound links on page Ti and

d is a damping factor which can be set between 0 and 1.

That's the equation that calculates a page's Page Rank. Most probably Google uses a variation of it but they aren't telling us what it is.

Google Page Rank as shown on the Google Toolbar is not updated very frequently. This is a reading of the actual PR and it's updated roughly every 3 months or so and so is based on the historical data - not current ranking data. In contrast Internal Page Rank (Actual Page Rank) is the Page Rank scores that Google uses as part of its ranking algorithm. Those scores are constantly being updated. This is due to the fact that page rank has been misused by many of the webmasters all over. As anyone can achieve high rankings by simply buying enough links from any website, or trading links with any unrelated website, Page rank has lost its value as a factor in ranking websites accurately.

The Google Toolbar is divided up into 10 equal linear ranges from 0 - 10. These linear divisions correspond to a logarithmic scale that Google uses. The actual scale is estimated to be between log base 5 and log base 10.This table's gives you an idea of how different toolbar PR is from actual PR.

In the long run, it's likely that after a few weeks, you'll have gained some internal Page Rank. You might see more traffic, as a result. But on, the Google Toolbar Page Rank may be the results are still the same. But it will be reflected only when Google will crawl for increasing the PR.

Ranking well in search for important keywords/phrases is far more important that the number shown in the Google toolbar for Page Rank. What matters is the relevance and quality of the incoming links

Google Page Rank is not always an indication of good traffic for your website. As the saying goes, "Good Sites get High PR, but not all High PR sites are good." Traffic is more affected by your content and other factors which leads to conversion.