Keyword cannibalisation occurs when two or more pages on a single website are optimised for the same keyword or nearly identical keywords. This tends to happen when you cover similar topics throughout multiple pieces of content. Such pages, intentionally or unintentionally, are optimised for the same keyword or very similar keyword phrases.

It’s called “cannibalisation” because your own website’s pages are directly competing with each other on the SERPs, therefore both eating into the same keywords. Such pages affected by keyword cannibalisation end up splitting the attention that search engines give to them, resulting in plenty of missed opportunities for the affected pages to accomplish their goals, whether it’s to drive traffic or convert leads.

How Does Keyword Cannibalisation Affect SEO?

All the hard work you put into optimising your website for search can be negatively impacted by keyword cannibalisation through any of the following ways:

1. Lower Click-through Rate (CTR)

The web pages that share space in the SERPs split the number of clicks they get from users browsing through the results. 

Instead of having multiple pages get a moderate CTR for the same keyword, you want just one authoritative page that gets a high CTR. This is because the higher the CTR, the better the chances for a page to climb the rankings, while a page that has a lower than expected CTR is more likely to drop in the rankings.

2. Fewer Backlinks 

Two or more pieces of content that tackle the same subject and, as a result, are optimised for the same keyword will generally have to share the same pool of websites that give backlinks to such content.

The number of backlinks matters when it comes to search rankings. Two web pages that both get roughly around 100 quality backlinks each will be outranked by a single webpage that has about 200 quality backlinks. 

3. High-Value Pages Ranking Lower

When you have more than one page competing for the same keyword, there’s a chance that the one page you think provides less value can rank higher than the other page you think provides more value.

It can be a page that simply has less detailed content compared to another. It can also be the case that one page has a high conversion rate but ranks lower than another page that doesn’t convert at all.