In my SES London travel SEO presentation last week, I discussed (in as much detail as you can in 11 minutes) a classic problem that many large scale sites can suffer from, “vertical PageRank siloing“, and how this issue can affect overall site indexation and traffic on your site.
In the session, I explained to the audience at the time that I’m giving simple, practical examples that I hope could easily be translated to any vertical, not just travel.
Classic issues with PageRank distribution in site architecture
In the session I started my site architecture section with a classic issue that can impact your SEO efforts and user journeys too. Imagine in the diagram below, the user (or search engine) enters your site at the homepage, and has to traverse a number of steps (or pages) to get to the content they’re looking for.
Every step down the site architecture we take, we’re at risk of getting lost or losing interest in what we’re doing (which is why I imagine Usability experts would normally always advise you to minimise steps along the conversion funnel to as few as possible). Search engines don’t get lost but they are computing a level of authority that each page in the chain receives based on the link juice (or authority, PageRank, MozRank etc) that page is receiving from internal and external sources of links. In principle, the further down a navigational hierarchy a page is, the less authority it receives from the page above.
As Rand explains in this classic Whiteboard Friday on flat site architecture, “Google has a threshold” where, if pages aren’t receiving enough juice they may not be included in the main index of organic search results. For a long time, this threshold was called the supplemental index, although I’ve not heard that term mentioned for quite a while. Regardless, there’s definitely a problem in the diagram above where, if there are too many steps between your homepage and the lowest tier of content, you could experience site indexation problems, particularly in very large industrial strength web sites.
A flattened site architecture
The solution to the problem we’re introducing in this diagram is to think carefully about the number of steps from top to bottom your navigation takes the user. This, very simple diagram shows a process of increasing the number of links from the homepage to the second level content tier, and the number of links from the second to the third, and so on. At this point, I’ll remind you that I was talking about travel based sites, whose architecture very typically comprises of a continent > country > region > city based (vertical) hierarchy. With that in mind, though we’ve solved quite a major problem by flattening our site architecture, we could easily be introducing a new one.
A flattened site architecture with PageRank
Let’s imagine for a moment that our homepage and some internal pages have attracted external links, perhaps enabling them to outrank their competitor’s pages. You may even observe these linked-to pages ranking generally higher than other, similar pages on the same domain. This is rather typical of any site and, in the diagram I’ve highlighted how the pages with more external links (and therefore more authority) might distribute their authority down the hierarchy to their lower tier child pages.
Why is this a problem? It isn’t, really. It’s pretty standard that some pages at the same level in your architecture will attract links and, when they do, they may be perceived to have more authority than pages at the same level. This is where I remind you that we’re looking at a specific vertical, travel – where a continent > country > region > city based (vertical) hierarchy can cause an issue that you may not have considered.
Vertical PageRank siloing
In this typical travel architecture example, we see our linked-to pages passing their authority down to their children. Obviously this is a very simple diagramatic approach, because some of that authority may be passed upwards to their parents through a breadcrumb. Just for the time being though, let’s assume that in our model, continents pass juice to countries in that continent, just as cities receive juice from their parent countries.
Solving the vertical siloing issue with a good cross linking strategy
Why not consider your horizontal, cross linking strategy as well as your vertical, site flattening strategy? In the diagram above I’ve tried to explain the likely impact by evening out the PageRank in each page. By considering ways to link across vertical silos that otherwise may not recieve much juice, you may be improving a significant chunk of your overall search engine visibility.
Ways to cross link your site
In the session I gave some general examples of ideas that would improve the cross linking architecture of your site. Those ideas included:
- Similar destinations
- Nearby areas
- Most popular / top countries
- Most popular / top cities
- Recently reviewed locations / hotels / resorts
Of course there are many other ways to cross link the content on your site. Moving away from travel and into retail, popular products, similar products and “other users searched for” are all great cross linking examples. Then there’s UGC and reviews, employing user profile pages to indirectly cross link sections of content.
Ways to identify the most linked to pages on your site
If you’re looking for inspiration before you design a cross link strategy, try checking out the Top Pages On Domain tool at SEOmoz. Having an awareness of the most commonly linked to pages on your site architecture can really help fuel new ideas for cross linking.
Update – the top pages on domain tool was included in SEOmoz’s wonderful Open Site Explorer. Check it out!
Image credit: Tokyo Tower, Japan by OiMax