Another feature was added today to our SEO software. One that I was really waiting for. Up until now, we could only see the backlinks and their PageRank, but that isn’t telling the entire story of PR juice contribution. The real story is hidden in the PageRank formula used to calculate PageRank and we’ve added a new column, called “PR Boost” which reveals more about that.
If you look at the formula used to calculate the PageRank (see image above), you can immediately notice that the PageRank gained from each link is not only influenced from the PageRank of the linking page, but also from the amount of links that page has. In the image above page A is linked from pages B,C and D. L() means the number of links the referring page has. So, we can see that because we divide the page rank by the amount of outgoing links the page has, the more back links that page has, the juice that comes from that link will be lower.
I also want to note here a common error I see, when people are looking at the PageRank of a site instead of the PageRank of the referring page. The PR boost is calculated based on pages, not sites. So, when you see a directory with PR 7, it doesn’t matter. Only the actual referring page PR matters, which might be 0 or not ranked.
So now, let’s see what SheerSEO has to offer here. If you look at the main referrers screen, you’ll find a new column, called “PR Boost”.
The PR boost is calculated with the following formula: 10^TBPR/num outbound links. As an example, let’s take a referring page with PageRank 2 and 100 outbound links. So, the calculation is 10^2/100=10*10/100=1.
The reason I use ^ (power) is because the PageRank we see in the Google toolbar is scaled, and not the real number Google uses. They only show us the scaled number from 0 to 10. The reason I use 10 as the base for the power part of the equation is pure guess. That number could be different, but 10 makes sense if you see how hard it is to advance in PageRank.
Please let me know your thoughts of this new feature,