PageRank or PR for short seems to be misunderstood by so many that this part of our SEO Tutorial we will try to explain the ins and outs of PageRank without getting too technical. Lets hope so anyway!
What is PageRank?
No better place for a description of PR than Google itself, from Google’s PageRank Explained page-
PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page’s value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.”
Important, high-quality sites receive a higher PageRank, which Google remembers each time it conducts a search. Of course, important pages mean nothing to you if they don’t match your query. So, Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to your search. Google goes far beyond the number of times a term appears on a page and examines all aspects of the page’s content (and the content of the pages linking to it) to determine if it’s a good match for your query.
Couldn’t have said it better myself, seriously though it’s clear from the above PageRank is very important to Google, it’s the foundation of their search engines algorithm and so very important to search engine optimization rankings. PR is created or transferred through links and it’s cumulative, a page with a high PR transfers more PR than a page with low PR making different PR valued links not equal in value from an SEO perspective.
Viewing PageRank
If you haven’t already installed the Google toolbar get yourself over to the Google Toolbar Download page and install a copy ASAP. When you view a page using a browser with the toolbar installed you’ll see a little green bar, hover over it to see the pages PageRank.
What Does a Specific PR Represent?
When you view a pages PR it gives a number between 0 (the lowest) and 10 (the highest), PageRank is based on a log scale, probably around base 6 to 8 (we don’t know for sure, but it doesn’t really matter if we get it wrong since it’s all relative). This means each PR point increase takes 6 to 8 times the effort as the last PR increase, this can be represented as a point system that is very helpful when analysing PR transfer especially for reciprocal link exchanges.
PR Points Table if PR is Base 8
PR1 = 8 points
PR2 = 64 points
PR3 = 512 points
PR4 = 4096 points
PR5 = 32768 points
PR6 = 262144 points
PR7 = 2097152 points
PR8 = 16777216 points
PR9 = 134217728 points
PR10 = 1073741824 points
As you can see the difference between PR1 and PR2 is not the same as the difference between PR2 and PR3. Higher a pages PageRank goes harder it is to go even higher on the Google toolbar display. It might help to imagine each point is the result of a link either directly or indirectly from other pages. Note: this isn’t accurate, but it helps to picture the difference between say a PR4 page and a PR7 page, PR4 pages takes 4096 links, PR7 page 2097152 links, that’s 512 times more links or 512 times the effort if all links were equal!
PageRank Formula
It’s not important that you fully understand the original PageRank formula to use PR to your advantage, but here it is for those who would like the details.
From The Anatomy of a Search Engine authored by the founders of Google Sergey Brin and Lawrence Page we have the the original PageRank formula-
We assume page A has pages T1…Tn which point to it (i.e., are citations). The parameter d is a damping factor which can be set between 0 and 1. We usually set d to 0.85. There are more details about d in the next section. Also C(A) is defined as the number of links going out of page A. The PageRank of a page A is given as follows:
PR(A) = (1-d) + d (PR(T1)/C(T1) + … + PR(Tn)/C(Tn))
Note that the PageRanks form a probability distribution over web pages, so the sum of all web pages’ PageRanks will be one.
PageRank or PR(A) can be calculated using a simple iterative algorithm, and corresponds to the principal eigenvector of the normalized link matrix of the web. Also, a PageRank for 26 million web pages can be computed in a few hours on a medium size workstation. There are many other details which are beyond the scope of this paper.
There’s probably been some changes over the years (most likely to iritate those offering SEO Services 
), but the guts of the PageRank formula is unlikely to change in the near future, so we can safely use it as a jump off point for PR analysis.
PageRank Simplified
The formula above is cumbersome to work with in the real world since it involves countless iterations of the calculation to reach a PR value and since we don’t know all the variables for a specific page we can’t accurately predict PR for any page using the original PageRank formula!
What we can do though is estimate PR transferred through a link, it’s rough and ready, but useful when setting up reciprocal link exchanges, you can determine roughly if a link exchange results in more benefit to your site or your reciprocal link partners site.
First we simplify the PageRank Formula to only determine PR transferred through a single link by replacing the PR value (PR(A)) with the corresponding value (which we will call PR(pts)) from the PR points table we listed earlier (repeated below). C(A) is from the original formula and represents the number of links from the page in question. For those interested we use 0.85 because it’s generally believed the dampening factor in the original formula (1-d) is 0.85.
PR(pts) * 0.85 / C(A) = PR points transferred through one link
PR Points Table using Base 8
PR1 = 8 points
PR2 = 64 points
PR3 = 512 points
PR4 = 4096 points
PR5 = 32768 points
PR6 = 262144 points
PR7 = 2097152 points
PR8 = 16777216 points
PR9 = 134217728 points
PR10 = 1073741824 points
Example PR Calculations
We have a PR5 page with 49 links from it, you want to setup a link exchange with this page which will take the number of links to 50. We look at the PR points table above and see PR5 equates to 32768 PR points, plugging these values into our simplified PR formula-
32768 * 0.85 / 50 = 557 PR points
We compare this figure on the table for the closest match. 557 is closest to 512 PR points or a PR3 (PR3 = 512 points). So a single link from the PR5 page above would likely result in a PR3 page if no other links are involved.
We repeat the PR calculation for your links page. You have a PR5 page with 15 links from it, if you setup this link exchange that’s 16 links, what would your link partner receive?
32768 * 0.85 / 16 = 1740 PR points (approx 3 times the PR points you’ll gain)
We compare this figure on the table for the closest match. 1754 is between 512 PR points (PR3) and 4096 PR points (PR4). So a single link from your PR5 page above would likely result in a stronger PR3 page (possibly a low value PR4 page) than your link partners if no other links are involved.
Easiest way to use this information is to compare the end results directly-
Partner Links Page: 32768 * 0.85 / 50 = 557 PR points
Your Links Page: 32768 * 0.85 / 16 = 1740 PR points
Your partner gains 1197 PR points (17540-557) than you do, this is enough to make two more PR3 pages (2*512=1024 is very close to the the extra points).
You then have to ask yourself is this link exchange in your best interest from a PR point of view. On the face of it no, but you should look at the page/site you are exchanging links with. Is it a popular site, are you likely to receive click thru visitors etc…? Enough PR points to create a couple of PR3 pages isn’t that much of a big deal, the calculation below is where you should think twice about a link exchange.
85% of the PR of a web page is transferred to the web pages it links to, shared equally between all unique links.
Potential link partners PR7 page with 199 links from it (200 after the exchange).
You have a PR6 links page with 9 links from it (10 after the exchange).
Partner PR7 Links Page: 2097152 * 0.85 / 200 = 8913 PR points (two PR4 pages).
Your PR6 Links Page: 262144 * 0.85 / 10 = 22282 PR points (five PR4 pages).
Even though the link partner has a PR7 page the large number of links from it makes it worth far less
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15 responses to SEO Tutorial – PageRank (PR)
I understand
I understand the basics, but it’s still pretty daunting isn’t it? I didn’t think that reciprocal links really counted for anything anymore?
Importance of PageRank
I not only agree that PageRank is important in the Google algorithm, I believe that HomePage PageRank is the top factor. The second factor is a boost that Google gives to the effective PageRank of a HomePage when the HomePage is competing for a keyword.
FASCINATING!!!
I’m new to the SEO game but it seems to me if we had a good estimate of the “Base” we could perform very accurate analyses.
The formula is simple:
let:
b= the base
N= total number of pages on the internet
Then:
b**10=N
check as estimate with N=1 billion ie. N=10**9
Then b=antilog (9/10) ~= 7.9 which is very close to your estimate of 8.
I know this may be an oversimplification but might be useful if we knew the total number of pages on the internet. So that’s the next question in my mind.
Just a thought,
Bill
SEO Tutorial – PageRank (PR)
If the basic concept behind reciprocal link exchange is giving and gaining pr points, does it mean that 2 webmasters who make a link exchange are SMART one and DUMB one? Because only one of them takes more then gives. If, theoretically, given points=taken points so no one benefits at all (the seo situation is the same before and after such exchange).
What is wrong with such reasoning?
PageRank/Link benefit during a reciprocal link exchange does generally result in one winner and one loser, so yes. The trick is to be the winner most of the time, use the PageRank Simplified Formula above for determining if a reciprocal link exchange is a good link exchange.
Also don’t forget it’s not just about PR/link benefit. There’s a lot of SEO benefit in just having a link point to a site because of the anchor text and the fact there’s a link to your site.
So if you know people you trust regarding link exchanges you can setup a groups of link exchanges where overall no one gains/looses much PR/link benefit, but have a few dozen links helps because they are links and they have SEO’d anchor text.
David
SEO Tutorial – PageRank (PR)
Yes , Page rank, effects google ranking, when we do link building, it is done on bases of pr’s . so as we add inbound links from the well know google ranking websites , the google ranking of the our existing website would also increase. thats how it works.
By the help of other well known websites, our website rank also boost up on the google. also these link transfer is done by mutual agreements.
Ah yes.
Pagerank. It is very relevant for getting traffic to your site. But keep in mind where the traffic is linked to. If users are linked to your site’s homepage, all the pages in your site profit because they’re linked too. However, your homepage PR may profit even more if the sites below your homepage are linked. As long as you have enough content there. Anyway, it pays if you think it over…
SEO Tutorial – PageRank (PR)
With the increasing influence and change of marketing focus to Internet, we have the usual unsavoury characters arriving on the scene. Where there is money, there is a scam. SMEs are particularly vulnerable to this as most do not have the resources, the time or the knowledge to distinguish a genuine SEO company from the fraudsters.
Let us start at the beginning and explain to the uninitiated what SEO (Search Engine Optimisation) is. Search Engines use a technology known as ‘spiders’ to seek out websites, making a record of the website content and then using their unique algorithm to judge whether or not the content of the website is relevant to the search phrase requested by a web user. Each search engine uses a different algorithm, putting different emphasis and weighting on different factors such as content, word density, meta-tags, usability, together with a range of qualitative and quantitative measurement matrices.
Search Engine Optimisation is a method which improves the visibility of a website within the results pages of free search tools such as Google, Yahoo!, MSN, AOL and so on, by strict compliance to the search engine’s algorithm. SEO actions should enhance the relevance of your website for your chosen keywords/keyphrases, improve usability and therefore increase the relevant traffic to your website.
Here are the telltale signs that should send the alarm bells ringing in your head and therefore avoid falling for one of the many scams that is plaguing SEO industry.
SEO Tutorial – PageRank (PR)
Any one tell me that how may I use pr2 to the blog comments….actually i have no idea about it….please explain this…and if possible please send me some pr2 blog list….it will be helpful for me…kindly do that for me….
thank you
how can i increse pr through link building or contant editing
it’s the true concept that the page ranking is a important factor to improve ur ranking on the web site .So we wil improve ur web site in yahoo,google and msn but sir i my opnion if we r using the concept of the log formation .We will be find the exact result .
if we r using the probability formate we will find the exact result in little bit of time…………….
And what is more important? is it PR or good ranking in google?
What do you recommend to start with, in order to obtain better results?
thanks
I dont think that PR is so important, i think you need better a good ranking in google.
Yes PR is still important, it’s a measure of the quality/quality of a pages links.
is pagerank effects google ranking?
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