Recently, in a conversation that Matt Cutts had with Rand Fishkin, Matt confirmed that Google does not see the use of NoFollow on your web sites as a spam tactic. Here are Matt’s exact words:
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
NoFollow in the Footer Nav
This raises some interesting possibilities for using this as a tool to concentrate PageRank in the places where you want to concentrate it. To see what we can do with this, let’s look at the SEOmoz blog’s footer navigation for an example:
This is a fairly common looking footer. Note how the “About”, “Our Services”, “Our Clients”, and “Contact” links are in the footer nav, a design element that shows up on every page of the site.
When you link to a page from every page of your site, the search engine is likely to think that you are saying it’s one of your most important pages.
Clearly, from a business perspective, the “Contact” page is one of the most important pages on the site. However, there is no reason to expect that it will rank highly for important search terms, no matter how much link juice you give it. You may, or may not, want the page to be in the index, but you don’t need to spend tons of PageRank on pages that will never rank.
A good solution for this is to use the NoFollow attribute on these four links. Note that you do not want to use the NoFollow metatag, because this will prevent the entire page from passing any link juice to any other page. This is not your goal.
In theory, this should signal Google that these pages should not be getting any link juice from the other pages of the site. If you want the pages to still be in the index, take one page, such as the home page, and do not apply the NoFollow attribute in the links to these pages from the home page. As a result, the search engines will still see the pages.
NoFollow in the Main Nav
Another application of NoFollow pages comes in when you are dealing with sites that cross-link between product categories. Let’s look at an example of this scenario:
In this example using the Digital Camera HQ main navigation menu, you could imagine that the Price Range pages change a lot, and are not likely to rank highly in the engines no matter what you do. In addition, the cameras listed under Most Popular are key pages that you want to pass the most PageRank to.
Assuming that this is true, NoFollowing the links to the Price Range pages would be a smart idea. As a result, you would stop spending PageRank on those pages, and have more to allocate to the other pages in the main nav, such as the Most Popular, and the Camera Brand pages.
As before, if you still want the Price Range pages in the index, just not with so much link juice, then go ahead and find one page and link to it without the NoFollow attribute from the page. The home page is once again a great place to do this from.
Summary
Based on Matt’s statements to Rand, it seems like these strategies should work for your site. As with all things of this type in the SEO world, there is no real guarantee that this will help you, but, intuitively, it makes sense. In addition, given the care that Matt and other Googlers must take in their public statements, it seems likely that there is little risk in trying it out.