Link depth

Link depth is the number of clicks required to reach a given page from the home page. Important pages should have low link depth.

Most often, the home page has the biggest number of backlinks and is the most important page on a website. This means that links on the home page are always a high priority.

Users and search engines alike navigate the website by following links. If a page is linked on the home page, it is a clear signal that this page is of importance. For that reason, pages that are crucial for the website should be linked on the home page or as close to the home page as possible - not more than two or three clicks away. In simpler terms, we can assume that PageRank is distributed equally among all links so proper website structure is extremely important.

If link depth is higher, the page will have low PageRank. Assuming the homepage has 5 links and one of them points to page A that also has 5 links and one link points to page A1, then page A1 is given 1/25 of the home page’s PageRank.

It is easy to conclude, that only a fraction of the home page’s PageRank is given to such pages. This, of course, is an oversimplification since the exact algorithms of how search engines distribute domain authority are not public. However, it is safe to assume that a page that requires more than 3-4 clicks to reach can be evaluated poorly by search engines.

Orphaned pages

Orphaned pages are another example of pages that are difficult to optimize. Orphaned pages are not linked on the website.

Orphaned pages may appear in search results in a few cases. Firstly, they may appear if links to these pages are placed in the sitemap file. 

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">

<url>
<loc>
https://www.example.com/page_A
</loc>
<changefreq>monthly</changefreq>
</url>
<url>
<loc>
https://www.example.com/page_B
</loc>
<changefreq>monthly</changefreq>
</url>
<url>
<loc>
https://www.example.com/page_C/
</loc>
<changefreq>monthly</changefreq>
</url>

Secondly, they may appear if a page has backlinks. 

In most cases, linking to a page within the website is recommended.

Another way for a page to be indexed without backlinks is setting canonical tags that point to a given page.

Planning the link structure

When you are planning the link structure, remember that the home page should link to all of the most important pages. When visiting online stores, I often see links to pages with products of little importance placed on the home page. For search engines, a link like this has the same value as links pointing to pages with crucial products. The best solution would be to place products that are less important on pages with higher link depth. 

Example

An online store sells children’s accessories and specializes in strollers. Teats can also be bought but they are a side product and do not generate much profit. I advise against placing links to teats on the home page. The best solution would be to link to strollers on the home page and place the links to accessories on the ‘category’ subpage. This way, link equity will be given to pages with strollers primarily.

How to check link depth? 

Pulno shows the link depth of every analyzed page. 

You can easily check how many links point to a given page. 

Click the icon with the down arrow, to see information about incoming internal links that point to a given page.

Internal link analyzer shows all internal links that point to a page and their link depth. This is a great way to analyze the website’s structure.

In the case of large websites, we are unable to place links to all of the most important pages on the home page. However, we should make sure that pages important to organic traffic are no further than three clicks away from the home page.

What can lead to link depth issues?

• Filters - if there are filters on the website and we sort results for many parameters, it can lead to the page having link depth issues.

    https://www.example.com 
    https://www.example.com/?sort=price //extra link level depth
    https://www.example.com/?sort=price&page=3 //another, extra link depth level

• Pagination - errors in structure can lead to several dozen pages appearing in search results. Each subsequent page requires an additional click. Thus, its link depth is higher. 

• Calendars - indexing of calendars is an example of an infinite link depth level. In most cases, such pages do not include useful content and therefore, should not be indexed.

Conclusion

I highly recommend keeping an eye on link depth and checking the number of incoming links. This aspect is often overlooked when, in fact, it can have a great impact on rankings in search engines. Correct internal linking structure and placing important pages close to the home page in opposition to less important pages will improve the visibility of a website in search engines. 

Sources: 

https://webmasters.googleblog.com/2008/10/importance-of-link-architecture.html