The Disproportionate Value of Deep Links

The impact of a few deep links appears be greater than what you might first expect. In today’s post I am going to explore why that may be the case, and how to leverage it. First let me go into my theory on the matter. For this example, let’s assume we have a high PR home page (PR7, 8 or 9). Let’s say it has 3 layers of content, consisting of an upper layer (categories), a 2nd layer (sub-categories) and a 3rd layer (detailed content).

If we apply the traditional PageRank algorithm, even the 2nd layer and 3rd layer pages should be somewhat competitive because they receive of PageRank from the rest of the site, but there are a lot of times when this does not seem to happen. It looks like the domain authority and trust is not distributed across a site in the same manner as pure PageRank. My theory is that this is caused by a filtering mechanism, which restricts the way that the lower layer pages on a site can accumulate the trust and authority of the domain.

Perhaps the page has a potential amount of link juice it can receive from its own domain, but if the page does not get any links on its own, then not all of that link juice is credited to the page. Here is an illustration showing what I mean :

Filtering Link Juice

When you get a deep link to a 2nd layer or 3rd layer page, our testing at STC shows that it has a much bigger impact than you might expect. Even a relatively low value link seems to bring large benefits to the ranking and traffic potential of the page, beyond what you would expect the value of the link to be. This may be because in addition to the link juice of the link, it also enables more of the link juice available to the page from the domain to be passed through, as shown here:

Impact of a Deep Link

And as you add more links the affect becomes more pronounced, as shown here.

Impact of Multiple Deep Links

Summary

Chances are the the actual algorithms that result in the behavior we have observed over time are actually quite different in concept from what I have outlined here, but this mental model of the value of a deep link does work for our purposes. When you have a 2nd, 3rd, or deeper layer page that you want to push in the rankings for competitive terms, you don’t necessarily need to get it hundreds of links. Just a few links will provide the page with benefits on a much larger scale than you might otherwise think.

Comments

  1. Spot on Eric – this is definitely the case as far as I’m concerned – even where the deep link pages’ target keyphrases are more competitive than the homepage keyphrases (often the case with ecommerce sites).

    At Fresh Egg the SEO team also noticed a pattern of ranking drops earlier this year, for deeper pages with no or hardly any inbound external links (ie previously living off the weight of internal PR alone). When we built links to these pages, they came back in, and higher than before. So it seems this factor was certainly notched up in the algo at some point.

    It all makes sense if you look at a natural linking pattern. Normally most natural links tend to go to the homepage. If a deeper page (eg a blog post or a particular product) is getting an unusual amount of attention and links, thats a good sign of an especially good piece of content on that site.

  2. Interesting thoughts, have you made any attempts to test this in a controlled environment?

    I must admit I’ve noticed that deep content on our site will get a sudden boost in PR when we have a site link to it directly, even if the page linking to our content doesn’t have much authority of its own.

    So to say that a possible filter is applied to the internal passing of PR is interesting. And that inbound links from external sites to that deep content will “open the flood gates” for your internal PR is also interesting.

    But it’s only a neat theory unless you can prove it through testing.

  3. hey Eric,
    You mentioned “our testing at STC shows”. Do you want to publish any actual examples that show this? That said, I tend to agree with what you say… as far as I can understand it, that it. :) Some of it goes over my head. ~ scott

  4. Brilliant food for thought Eric – the kind of post that makes you sit and think for a while. Bookmarked, Sphunn, Tweeted.

  5. Eric I think you have great expertise in link building. The concept of link building which you shared is really awesome. I appreciate you for posting this nice information and keeping us informed about latest strategies. I will follow this strategy while doing link building task for my clients. Thanks a lot.

  6. Although in PR points the internal link may be higher, an external link has more true value as it conveys trust: offsite linking is either commerce or recommendation.

    In such a mental model a low PR “trust” link trumps a high PR “no trust” link.

    Good, mind-tickling post, Eric. Thanks!

  7. Eric I can send you site that perfectly shows how this is not true. Email if you like to discuss how this can be.

  8. Jaan – Thanks for sending the example site over. Actually, it does clarify something I should have mentioned in the post. The post assumes that the home page has the most link juice to it, as is the case with the great majority of sites.

    The phenomenon I described above does not apply if you start your link building by obtaining links to deep pages. In effect, there is little or no juice to bottleneck, so adding deep links does not unlock anything.

    In most sites, there is an unrealized potential in the links to the home page and the site overall. If your site does not have unrealized potential you don’t see the affect I have described here.

  9. Excellent post, I will have to start developing more internal links as soon as possible.

    Am I the only one that thinks the word “Link juice” is the most horrible term ever coined?

  10. No Justin, you are not the only one. :-)

  11. thanks dude, we never gave importance to deeplinks, but this seems to be an eye opener

  12. We have been working on this for a while and it’s great to see that you are highlighting this paticular subject and it’s importance.

  13. I don’t think that anyone was doubting this theory to begin with, but it’s nice to see it drawn out with diagrams and etc. I think that this is especially important with eCommerce stores that go even deeper than 3 levels, need to get all of those product pages indexed and listing!

  14. This does confirm that the further a page away is from the home page the less importance it is given. I had not considered the possibility of a filter keeping trust and authority from those pages. This is very useful information, especially for ecommerce sites.

  15. I have undoubtedly noticed this as well. I have ranked for many fairly competitive terms (locally modified) with just a few, very average deep links from directories. It’s great to see it confirmed in such a clear manner.

  16. Interesting, I have just been observing this effect while researching for a client. Your post makes sense but it could do with some empirical testing.

  17. It is a very key element of any successful link building campaign, and that true value is likely why a number of directories and assocations don’t allow for deep linking.

    It can be fun to see how the refinement of some deep links allow you to challenge a trusted and authority domain and rank well on high value keywords.

  18. I think this is because a 2nd or 3rd layer page on a very authorative domain will piggyback from the domain’s authority. In which case, as you said, even a low PR anchored link will blast that page high in the SERPs. Just look at some Amazon pages for example which rank high for very competitive terms with few backlinks.

  19. You are absolutely right. Deep linking can increase the authority given to the secondary pages helping them also rank independently. Great article.Thanks for putting together the research.

  20. An excellent post and very well explained. For me the concept helps corralates to what Rand Fiskin recently explained in his post about crawl and indexation issues – http://www.seomoz.org/blog/diagrams-for-solving-crawl-priority-indexation-issues

  21. “In most sites, there is an unrealized potential in the links to the home page and the site overall. If your site does not have unrealized potential you don’t see the affect I have described here.”

    On the other hand there is still merit in some deep linking in order to maintain the ‘naturalness’ of your inbound links.

  22. yes, I agree, it’s obvious that if the page is not popular with the outside community it’s not going to be popular with the search engines.

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  23. SO let’s say you have an article on a high PR site. If you back link that article by your theory this should open up the PR to flow to that article page. If this is the case then every article and press release should be from high pr sites and needs to have a backlink. This would also apply with guest blog post as well. Is this what you are saying?

  24. Thanks for sharing..!!

  25. Thanks for sharing this important stuff

  26. This is great information about to the search engine optimization. Thanx for sharing ith us. keep it up.

  27. This is my first time i visit here. I found so many interesting and useful stuff in your blog especially its discussion. From the tons of comments on your articles, I guess I am not the only one having all the enjoyment here! keep up the good work.

  28. Thanks for sharing :)

  29. So on a lower PR site like a PR2 or PR3, will deep linking help the overall ranking of the site or just those pages?

    In other words, let’s assume you have 100 external inbound links only to the home page and it is a PR2. You are sitting at #12 on Google. If you added 100 more links, but all of them deep, could it buoy the entire site up to page 1 (or would only those deep pages rise)?

    Are you getting “the whole is greater than the sum of its parts” thing working?

    • Scott – Links to any page to your site will benefit any and all the other pages linked to on the site, but it will benefit the page receiving the link (the Linked Page) the most. To use a slightly different saying “a rising tide lifts all boats”. How much each page benefits depends on the internal linking structure of the site. The pages receiving the second largest benefit will be the ones that the Linked Page links to directly, for example.

  30. Indeed a thought provoking post – essentailly its as if you have kicked into touch the deep page, a natural link mix would consist of links pointing to the relevant deep pages – howevere remember to make sure not to send an inappropriate amount to the deep pages – generally a sites homepage will absorb the most links – with a sprinkling going to the deep pages.

    Good read!

  31. Great article. What tools do you use for link building?

    • Hi Brighton SEO – We use a variety of tools, including Linkscape, and our own proprietary tools. There are other good tools out there, such as Majestic SEO.

  32. thanks eric :)

  33. Thank for sharing this observation. This is true my home page has the highest rank then the sub-pages have a little lower PR. As the levels go so do the PR decreases.

  34. You are right the deeplinks are very important..

  35. Thanks!

    I’ll start making some internal links :)

  36. The Google algorithm is obviously a lot more complex than to reward deep links to such a degree. Good research, but needs some real world test examples

  37. Nice article. Looks like I need to do some internal linking. Usually that’s not something I have spent much time doing, but it looks like a reasonable thing to do when linkbuilding.

    Thanks.

  38. Excellent and very much informative post, but if the page rank is not higher , it does not go for the effective search engine optimization. How can i overcome it?

    • Eric Enge says:

      Not a simple question! Ultimately, at the end of the day, you do need to build great content that will drive the PageRank you need. When you have that, the thoughts in this post will apply.

  39. I always build lots of links on my front page – and keesp forgetting to build deeplinks. I guess that is why I always fails to get toprankings :)

  40. With the latest algorithm update, I think Google is looking more at the website as a whole rather than focusing on just individual web pages. If that is the case then there is new meaning to this 3 year old phrase “deep linking”.

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