Pagerank Sculpting, what is this? How one can sculpt an unmaterial thing like pagerank? In fact we don’t sculpt PageRank, but it’s distribution within a site. All of us who have one or more sites must admit that some pages are more important than others and we would like that some of them also occur between the results of research, not just our home page. I don’t know who had this idea of modeling the site, but the concept is this: there are important pages within the site that I care about and the others I care less because they have no relevance to the search engines. The idea is to pass more PageRank from those non important to the important pages: it is a redistribution of PageRank. And how we can do it?
The technical procedure is very simple and is accessible to all webmasters. The tip is the using of the tag "nofollow" (again this famous tag). The pages that you want to ignore must be linked from other pages using that tag. In this way the internal links do not pass pagerank to those less important pages, and the available Page Rank is distributed to the most important. Easy to apply and seems also to be very useful in some cases. But is this concept works, is it correct? By my opinion no and I will go to explain my point of view.
Who is familiar with the formula for the calculation of pagerank knows that the pagerank passing to other linked pages drop by a factor of damping (this is not of our interest for this reflection) and depends on the quantity of the number of links. The originators of this technique are confused and thought: putting nofollow tag fore some links, these will not be taken into account for the distribution of pagerank and here is the error. Number of links are used as the probability that one of the links on the page is clicked by a visitor. But the visitor does not see if a link has been tagged and not change anything in its intentions.
My conclusion is that this technique not only does not help the site, but it hurts: the pages linked with nofollow lose pagerank and don’t pass anything to important pages and at the end of the story, all the site is penalized because with less pages, drains less page rank from external links that point it. To those who are not convinced by my argumentation and that in any case would like to try this technique, I can say that this is recognized as legitimate procedure directly from Goolge. If your findings are different from mine, let me to know about.