Google’s views on PageRank sculpting
Summary:
Matt's answer:
What are your views on PR sculpting? Useful and recommended if implemented right, or unethical?
I wouldn’t say it’s unethical, because it is stuff on your website, you’re allowed to control how the PR flows around within your site. I would say that it’s not the first thing that I would work on. I would work on getting more links, having higher quality content, those are always the sort of things that you wanna do first. But if you have a certain amount of budget of PR, you certainly can scope your Page Rank. I wouldn’t necessarily do it with a nofollow tag, although you can put a nofollow on a login page, or something that is customized, where a robot will never log in, for example. But a better, more effective form of PR sculpting is choosing for example which things to link to from your homepage.
Having great content is a better way to rank well
Imagine you’ve got two different pages, you got one product that earns you a lot of money every time someone buys, and you got another product where you make ten cents. You probably want to highlight the first page, you want to make sure that it gets enough PR that it can rank well, so this is more likely to be a page that you wanna link to from your homepage. So, when people talk about PR sculpting they tend to think nofollow and all that sorts of stuff. But in some sense, the ways you choose to create your site, your site architecture, and how you link between your pages is a type of PR sculpting. So it’s certainly not unethical to have all the links come into your site and then you decide how to link within your site and how to make the pages within your site. I do think that having more links because you have great content is a better way to rank well because it’s a second order effect to be sculpting your PR. It can be useful but it wouldn’t be the first thing that I’d do.
by Matt Cutts - Google's Head of Search Quality Team