Techfrog.org

You all may be knowing what Pagerank is. For those of you who are unaware :
PageRank is Google’s way of giving a specific value to how popular your website is. It ranges from 0 to 10 and is a Whole number
Pagerank is determined on the number of ‘votes’ other websites cast for your website. A ‘vote’ is simply when another website places a link to your website on one of their pages. Generally, the more ‘votes’ or ‘backlinks’ you have pointing to your website, the higher your Page Rank will be. Page Rank is one of the many factors that Google considers while determining your rank in search results.
So how does Google calculate Pagerank?
Here’s the formula :

PR Boost = (1-d) + d*[PR(s1)/Links(s1) + PR(s2)/Links(s2)....+ PR(sn)/Links(sn)]

Where :
d = Damping Factor (Usually 0.85)
s1 = The page where your backlink is placed
PR(s1) = PageRank of the page where your backlink is placed
Links(s1) = The total number of Links(Outbound and Internal) on the page your backlink is placed.

So, from this we can deduce the value of our link on another site will be higher when :
1) The PR of The Page is higher.
2) The total number of non-nofollow links is lower.

We don’t have control over the damping factor though, since it is somewhat constant at around 0.85.

You may have seen some websites having many of links on their pages made nofollow.

What is nofollow?
=> ‘nofollow’ is an attribute assigned to the <a> tag of HTML. It is used in the following way

<a href=’http://www.yourdomain.com’ rel=’nofollow’>YourDomain</a>

This means that search engine bots will not interpret this link. They will simply ignore it and continue crawling other parts of your Website.

The benefit of having the nofollow tag is, you can maintain the link juice you provide to links on your page. Suppose your homepage is PR5, you may have many links like ‘login’, ‘register’, ‘Privacy-Policy’,etc.. as default, these links are not nofollow, hence the distribution of your PR is even amongst all links. So if you may want your ‘contact’, ‘about’, ‘forum’,etc. pages to get more priority, the only way is make other links nofollow.

Considering the algorithm given above, having a backlink on a PR5 page with 80 total links provides more link juice/value than having a backlink on a PR7 page with 120 total links.

Here’s the math : (excluding the damping factor for now for comparison reasons)

1) Value on the PR5 page = 5/80 = 0.0625

2) Value on the PR7 page = 7/120 = 0.0583

Unexpected right?

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