If you are a large online retailer, you’re looking at thousands upon thousands of pages that have the opportunity to get crawled and indexed in the SERPs (search engine results pages). You’re also looking at near infinite choices for how you interlink all those pages. Out of all those permutations, there is one configuration that is the most optimal from an SEO perspective. That’s because it maximizes the flow of link juice (e.g., PageRank if you’re speaking purely in Google terms) to your most important pages and minimizes (or cuts off completely) the flow of link juice to your least important pages. The most important pages are the ones that have the most potential to rank highly for the targeted keyword themes, to compel the searcher to click, and to drive that visitor toward a “conversion event” such as completing a purchase of one or more high-margin products.
To achieve that search engine optimal configuration of your internal linking structure, you need to think strategically about how you “spend” the link juice that has been bestowed on your site through inbound links.
Think of these inbound links as “votes,” and remember that we’re dealing with a meritocracy here, and not a democracy. In other words, not all “votes” are created equal. Of all the pages of your site, it’s probably the home page that has earned the most and best votes and is the most endowed with PageRank. Therefore, your site’s hierarchical tree structure largely determines how your link juice is “spent” within your site. So, I hope you organized your site tree with SEO in mind, not just usability!
One of the most powerful, and most underdeveloped, on-page SEO tactics is rejigging your internal hierarchical linking structure to optimize the flow of link juice. I’ve written about this before, in the context of tag clouds and of breadcrumb navigation. But there’s another way to optimize to your internal linking structure: selectively “nofollowing” some of your internal links. Google engineer Matt Cutts refers to this tactic as “sculpting your PageRank.”
Rel=nofollow (which can be inserted into the HTML of the link like so: <a rel=nofollow href=”whereever”>) was originally developed by the search engines to remove the incentive for blog comment spamming, and the search engines positioned the nofollow as a way to not “vouch” for a link (i.e., not treat it as a “vote” that passes link juice). But the engines have evolved their thinking. They realize now that rel=nofollow is a much more versatile tool than when it was first conceived. Matt Cutts of Google was quoted recently as saying:
“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.”
The way I interpret Matt’s reference to “link-level granularity” as “laser-like precision” — as in: the size and shape of your site’s navigational hierarchy is your blunt instrument and rel=nofollow is your scalpel.
In my interview with Matt Cutts at PubCon, Matt confirmed that links with rel=nofollow weren’t “used for discovery; they are not used for PageRank; they are not used for anchor text in any way.”
Speaking of anchor text, that brings to mind another use for nofollows on internal links: when the anchor text is suboptimal and the link is redundant. For example, I’ve seen countless blogs with multiple links to the same permalink page: one uses the post title as the anchor text, and the others contain such throwaway anchor text as “Continue Reading,” “Comments,” or “Permalink.” In fact, that was one of my Twelve Mistakes that Most Bloggers Make (Mistake #5, to be exact). On ecommerce sites, you’ll see this same phenomenon manifest itself as redundant links leading to product pages: one uses the product name, the other uses throwaway phrases like “Click Here” or “Order Now” or “Product Info” or the product’s price; or the link is an image of the product with an alt attribute of “product_image.”
The first place to begin sculpting PageRank is on your home page, because that page holds so much weight in the search engines’ eyes. Typically, the home page needs fewer links to new or recently-reviewed products, and more to top-selling (and high margin) products, categories, and sub-categories. Often, I’ll see that a retailer’s home page has well over Google’s recommended “100 links per page.” In my aforementioned interview with Matt, he offered further insight into Google’s “100 links” guideline:
“The reason for the 100 links per page guideline is because we used to crawl only about the first 101 kilobytes of a page. If somebody had a lot more than a hundred links, then it was a little more likely that after we truncated the page at a 100 kilobytes, that page would get truncated and some of the links would not be followed or would not be counted. Nowadays, I forget exactly how much we crawl and index and save, but I think it is at least, we are willing to save half a megabyte from each page. So, if you look at the guidelines, we have two sets of guidelines on one page. We have: quality guidelines which are essentially spam and how to avoid spam; and we have technical guidelines. The technical guidelines are more like best practices. So, the 100 links is more like a “best practice” suggestion, because if you keep it under 100, you are guaranteed you are never get truncated.”
To get some insight into how some of the bigger online retailers were sculpting PageRank, I culled through Internet Retailer magazine’s “Hot 100″ Retail Websites using the SEO for Firefox extension, which highlights nofollowed links in red. I wasn’t surprised when I found that hardly any of them employed “nofollows” on their home page to sculpt PageRank. In fact, I found only one doing it to any real degree: Altrec, an outdoor sports retailer that competes with the likes of REI and Cabela’s. Altrec have chosen not to squander their hard-earned link juice on scrolling headlines, Live Chat, “My Store,” and social bookmark services. Admittedly, they could have gone further and nofollowed “Today’s Deal,” “Give Us Your Feedback,” “Shipping & Ordering,” “Privacy & Security,” and “EASY Returns,” to name a few.
Digging a little deeper, I found that Altrec implements nofollows across their site. Sizes, expanded views, duplicate pages, and hot links are all “nofollowed” to sculpt PageRank. As a result, they’ve reduced duplication and passed a larger amount of link juice to their category pages, which appear to rank extremely well. Heck, even product pages have a PageRank of four in many cases. Admittedly, there are many more opportunities for them to further hone the flow of link juice, but they’re off to a great start.
So, what are you waiting for? Get sculpting!
Stephan Spencer is founder and president of Netconcepts, a 12-year-old web agency specializing in search engine optimized ecommerce. He writes for several publications and blogs at the Natural Search Blog. The 100% Organic column appears Thursdays at Search Engine Land.
Opinions expressed in the article are those of the guest author and not necessarily Search Engine Land.