The abbreviation PR is commonly known as “Public Relations”. Not so in Online Marketing. Here PR stands for the link algorithm PageRank which is named after one of Google’s’ founders, Larry Page. It is used by the Google search engine to “measure” the relative importance of a website within its set of hyperlinked pages.
You probably know this question: “How pretty am I on a scale from 1 to 10?” If you haven’t said it yourself, you might have heard it from a girlfriend or spouse. If not that, then you probably heard it in one of the several movies that use this particular line. Rating something (or someone) on a scale from 1 to 10 is common. In simple terms, the Google PageRank does the same with websites.
How to calculate the PageRank
The basis for PR calculations is the assumption that every website in the World Wide Web has a certain importance which is indicated by the PageRank (0 being the least and 10 being the most important). The PagRank is calculated by the number and value of incoming links to a website.
Initially one link from a site equaled one vote for the site that was linked to. However, later versions of the PageRank set 0.25 as initial value for a new website (based on an assumed probability distribution between 0 and 1).
The value of incoming links
Before you start collecting links from several different pages, you should know the value each and every link has.
The value of inbound links is determined by the amount of outbound links from the linking site and its PR. That is, because the PageRank of the linking site is divided by the total number of outbound links the page has.
A page that is linked to by several relatively important websites (those with high PageRank themselves) has value, meanwhile a website that has no incoming links is considered unimportant. The more incoming links from high value websites you get the better for your website.
To simplify that process, let’s look a a universe with 4 websites only (A, B, C, D).
- A has 1 outgoing link (to D)
- B has 2 outgoing links (D and A)
- C has 1 outgoing link (to D)
The PageRank of D equals the sum of the PR of the linking website(s) divided by their outgoing links.
From this example you see that links from pages with a high PR and less outgoing links are worth more than many links from low PR pages with thousands of outgoing links.
From the above example you can see that your link value decreases with the amount of links you place. Some websites have many incoming links, but they don’t link to other pages themselves. Those are considered “sinks”. According to the theory of the random surfer (someone who clicks through the internet randomly) that means, everyone would eventually somehow end up at a sink-website. To balance this phenomenon and in order to be fair to non-sink pages, the PR of websites without outbound links is distributed evenly among all other websites.
- Recommended read: Google PR 3 for a Website with no Content
How should a great link profile look?
Now based on the PageRank, how would a good link profile look like? Based on PR only you would go for high value, high PR websites that have only few outgoing links. Obviously this fact will increase the difficulty of getting them to link to you. Based on PR only this would be the best way to go. However, there are more factors to be considered in building a great link profile. Especially after Google algorithm updates “Penguin” and “Panda”.
It all comes down to building a natural link profile. You should try to avoid anything that you do just for SEO purposes, but that wouldn’t come natural to a non-SEO. Instead use natural link texts and sources that would naturally be related to your site. Also include all types of back links (not just high PR back links, but also low PR ones).
Do let me know if you still have any query regarding Page rank calculation?