PageRank (or PR) leak
One of the most vehemently debated subjects is whether or not there is such a thing as "PageRank leak".
The curious part is that many people will deny the existence of PageRank leak - and at the same time believe that they can increase their PageRank by having a well-linked site - without realising that this is the other side of the coin:
Hagstrøm's first law: For every increase in PageRank, there is an equal and opposite PageRank leak.
For this demonstration let's assume two sites - both with a simple structure like the picture to the left.
|How to specify two sites with 5 pages each|
The result is that both sites have a total PageRank of 5. If you haven't got the spreadsheet, you can see the result on this spreadsheet.
|How to link from one site to another|
Guess: Page5 had a PageRank of 1 in the first iteration. Since Page5 is now linking to 5 pages (4 internal pages + Page8) - and with a damping factor of 0.85 - we would assume the loss to be 0.85 * (1/5) = 0.17 - i.e. negligible.
Now let's stop guessing and take a closer look at