Can I use nofollow links internally to channel PageRank?

&First off, credit where it is due: My friend and SEO wizard Leslie Rohde told me about using nofollow to channel and manage how PageRank flows on a site quite a while ago, and while I was skeptical and concerned it was "gray hat" SEO or worse, it turns out he was right and I was wrong. It's totally legitimate and acceptable and indeed Google blogger Matt Cutts recently came out and stated on SEOmoz that "webmasters can feel free to use nofollow internally to help tell Googlebot which pages they want to receive link juice from other pages."

His specific answer was more detailed, of course:

"The nofollow attribute is just a mechanism that gives webmasters the ability to modify PageRank flow at link-level granularity. Plenty of other mechanisms would also work (e.g. a link through a page that is robot.txt'ed out), but nofollow on individual links is simpler for some folks to use. There's no stigma to using nofollow, even on your own internal links; for Google, nofollow'ed links are dropped out of our link graph; we don't even use such links for discovery. By the way, the nofollow meta tag does that same thing, but at a page level."

This is pretty big news in the world of search engine optimization, actually, and I'm really glad you asked this question. For those of you who aren't steeped in SEO, you might recall that the idea of "nofollow" was to combat spammers who added bogus comments so that they would gain links from blogs to their own sites and thereby game the system. I've written about it here: penalized for nofollow links?

It worked pretty well as a solution, though other methods of combating blog comment spam have arisen that are far better (hat tip to the amazing Akismet system especially). Nonetheless, the idea that you could add links to your Web site that weren't seen (or at least ranked) by search engines is a powerful one and it's no surprise that people started to think through different uses.

Now let's look at my own weblog here. I have a lot of pages on this site, including pages that are present for my readers, but aren't pages I really need to have show up as a result on a Google search. An example? My ask a question page. By default, I'd link to it like this:

but then since PageRank is transmitted to linked pages as a formula (PageRank value of any given link = PageRank of the current page / number of links), I really don't want to waste even a fractional PageRank on that page. Instead, therefore, I can do this:

(I've highlighted the change to make it stand out, of course)

Now I'm in control of how that PageRank that I've earned for my individual pages is disseminated throughout the site, and that's a good thing. Leslie pegged it when he told me months ago that any secondary pages, anything like a sitemap, contact us, about us, or similar page should always be nofollowed. He's exactly right.

More importantly, with the recent information from Matt, we now can modify our pages with assurance that it isn't anything dangerous, isn't a technique that can get you into trouble with Google or otherwise backfire.

I hope that answers your question. My advice: go for it!