Check out the ”US eCommerce technical SEO status” report from Boostsite!

Keyword cannibalization

What is keyword cannibalization?

Keyword cannibalization occurs when several sub-pages compete for the same keyword. In such cases, robots rendering and interpreting subpages may have trouble defining a single, specific URL corresponding to a given keyword.

How to check if the cannibalization occurs?

Keyword cannibalization occurs when, for a given keyword, Google search results once show one of our website’s URLs, and then another one, followed by another one and so on. As a result, the ranking for the keyword is split, so to speak.

Examples of cannibalization

Keyword: “men’s sports shoes”

Sample search results:

Search results for the same keyword less than a week later:

This illustrates that the same keyword, at two different time intervals, returns different ranked URLs (for the same domain – journeys.com).

Causes and effects of cannibalization

How does it affect ranking?

Keyword cannibalization is practically always detrimental to rankings. As you can see from the example above, the keyword achieves a similar ranking, but if the search results contained only one URL for the keyword, its ranking would be higher. At this point, I don’t want to estimate what the exact ranking would be for the above keyword without cannibalization, but I am very confident that it would be higher (which I think is a good enough reason to fix the problem).

How does this affect the domain?

When keywords move down in the rankings, this also drives down both traffic and the number of users – then, most likely, the domain’s value in the eyes of Google’s algorithm will decrease as well. I’m not 100% sure about the specific decline of the domain value, but as we can see from experience – if the website is no longer visited – the rankings also decline, even for sub-pages and keywords directly associated with the cannibalization.

This leads to the conclusion that cannibalization occurring anywhere (especially on frequently visited sub-pages) can affect the value of a domain. As is the case when it comes to topic silos, where each sub-page within a given silo (and not just the one that is most boosted) can see an increase in rankings.

How to eliminate the issue with cannibalization?

There are quite a few ways to eliminate cannibalization, but it is always a good idea to choose the most effective one for a particular case. Here is a list of popular methods to eliminate the problem of sub-pages competing with each other.

Merging some pages together

If you have 2 articles on a similar topic (and most importantly – with a similar sounding title tag), consider merging them into one. Unless one is complementary to the other, and they cover more or less the same subject, just in different words – in most cases there will be no point in creating a separate URL. This is because Google may assume that both sub-pages cover the same topic to a similar extent – so it may display either one or the other address for the same keyword in the search results.

Using a canonical tag

This example is somewhat similar to the one above, with a slight difference: if you decide that you don’t want to have two pages, but one of them is practically identical and uses largely the same words – combining all this into a single URL may not bring any additional value, so it’s simpler to implement the canonical attribute that will inform Google that this second page is actually the same as the first one and is not a duplicate. Similarly, you can use 301 redirect. Then the effect will be similar with two small differences:

1 – Canonical may not work if some of the text does not match up

2 – Redirect will make the original sub-page inaccessible to the user (canonical will make it fully visible)

De-optimization of duplicates

Sometimes the cause of duplication can be, for instance, the very title of a given sub-page. Even though there may actually be 2 different pieces of content, but the title will, for example, start with the same keyword keyword – Google may also consider that it is the same thing. Then it may be helpful to de-optimize one of the titles by removing a cannibalized keyword keyword.

Blocking the indexing of duplicates

The simplest option to eliminate cannibalization from, let’s say, two URLs is to de-index one of them. However, this option has the disadvantage that it will not bring any value from the URL that is indexed. For this reason, I always consider whether I can use the second URL in any way and if it turns out that:

1 – the URL does not generate any traffic

2 – it doesn’t contain any external links

3 – is a relatively new URL “not rooted” in the site structure

4 – the content on the sub-page is of no use to me

then I might consider just de-indexing it, since I won’t benefit from it in any way.

Effects of improvement

The effects of improvement with cannibalization issues are virtually always positive. We cannot calculate exactly, e.g. that if there is cannibalization on 2 URLs for keyword “x” and we get a rank of e.g. 10, then, once we eliminate the issue, the rank will reach e.g. 5. We don’t know that. We do know, however, that the rank will most likely be higher.

How to prevent cannibalization?

First and foremost, we need to carefully lay out the structure of the website. Be sure that the articles are complementary at most, and not cover the same topic at different URLs. The same goes for categories – subcategories or even products (in the case of e-commerce). If they sound different, if they have different titles, if they don’t address the exact same subject – then the risk of cannibalization drops significantly.

Leave a Comment

Boostsite Sp. z o.o.
św Mikołaja 7
50-125 Wrocław, Poland

english polski