I want to spend some time better understanding page rank before we move onto how to make your site PR friendly. In the first article we discussed what Page Rank was and where it came from. We tried to make it a primer, but there was still some confusion, so lets break it down further.
- A website has a maximum amount of PageRank that is distributed between its pages by internal links.
- The maximum amount of PageRank in a site increases as the number of pages in the site increases.
These first two rules are important. Your internal site rank is based upto a point on the amount of quality content you have on your site, but there is a maximum amount of PR you can have.
So it is important to understand that you need content, and secondly you need to arrange it in an orderly fashion. So we need to understand internal linking Google Juice.
Any Page that does not have links into it does not have page rank and hence is not included in calculation.
This sounds obvious because a spider needs a link in order to get to it, but with a blog that is not true anyway. Your posts and pages will link off the main site and tag and cat pages.
Here are some examples to illustrate how the calculation works. Please note these are not your actual PR for Google, there are many other variables taken to get to that. This explains how best to understand your internal PR so what ever the real number is is maximized.
http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_1-150x150.gif 150w, http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_1.gif 400w" sizes="(max-width: 240px) 100vw, 240px" />
Using the above picture, we can calculate the PR of each site according to the Page Rank algorithm.
After 1 iteration:
- Page A = 0.15
- Page B = 1
- Page C = 0.15
After 100 iterations:
- Page A = 0.15
- Page B = 0.2775
- Page C = 0.15
So total Page Rank for B is: 0.2775. Given that the theoretical PR is 3, we have a long way to go to juice up our site.
http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_2-150x150.gif 150w, http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_2.gif 400w" sizes="(max-width: 240px) 100vw, 240px" />
This next example, we link every one to everyone else. The answer is 1 for each page and what ever you do, it will stay at PR1. This is of course no good because we want to have some pages rank higher and others lower. This presumably is your front page and some other key pages you want to rank.
http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_3-150x150.gif 150w, http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_3.gif 400w" sizes="(max-width: 260px) 100vw, 260px" />
In this example we are linking back and forward to page A. The results are (after 100 iterations):
- Page A = 1.459459
- Page B = 0.7702703
- Page C = 0.7702703
You can see that Page A has a much bigger ranking than the other pages. What has happened is B and C has given Google Juice to Page A. You see that a quick add up and the Site PR ranking is 3 so none has been lost.
http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_4-150x150.gif 150w, http://bluecowhosting.com/blog/wp-content/uploads/2009/04/page_rank_4.gif 400w" sizes="(max-width: 260px) 100vw, 260px" />
In this example Page C has added a link to Page B. The results are (after 100 iterations):
- Page A = 1.298245
- Page B = 0.9999999
- Page C = 0.7017543
Notice firstly that Page C has shared it’s juice with Page A and B, which means A has lost some PR Juice. This juice has ended up with Page B whose ranking has increased.
Notice that there are two optimal structures to maximize Site PR, the first is everyone links to everyone else. This will maximize the Site PR, but no page can get more than one. So this is both impractical.
The second is everyone links to the front page. That we maximize the first page, but it too is impractical. In order to make our site readable, it needs to link to other pages and other sites, so this too is impractical.
The key take away is that you need to decide on a few key pages on your site that matter (including the main page) then think out your internal linking strategy. For example, this page is going to link back to Part 1 only, so that the Juice goes to that page, and then you can find the rest of the series on that page.
You will inevitably notice that there is a trade off between PR and readability, Next time we will discuss the impact of external linking to your PR structure.