How Do Sub-domains Affect SEO

Is sub-domain use a great SEO strategy? This has been a debated topic for years with both sides of the divide having a lot to say about the impact sub-domains have on SEO. The goal of a sub-domain strategy is to demarcate content, giving various categories their own space on the root domain. People have different uses for them. Some of these reasons are appropriate while others are greatly misguided. What matters at the end of the day is how these applications affect SEO.

The good

  1. Domination of the SERPs

Search engines like Google treat sub-domains as websites on their own. Using them can give your content multiple chances of appearing in the SERPs since each sub-domain has a separate opportunity to rank. However, if your main domain is not ranked well for your targeted keywords, sub-domains will only further divide the limited inbound links and hurt the ranking of both the main domain and the sub-domains. If your root domain can generate enough traffic to have a top 3 ranking, then you can afford directing some of the traffic to a sub-domain.

  1. A sub-domain inherits the credibility of its root domain

In as much as a sub-domain is treated as a brand new website by the search engines, it inherits the trust and credibility of the root domain. Google passes the history of the root domain to its sub-domains. This means that it does not go through the lag to indexation seen on brand-new domains. It is therefore more prudent to create sub-domains than to register brand new domains.

The bad

  1. Damage to your bottom line

Sub-domains can hurt your conversion in the event search engine results fail to produce desired results. If search engine results send visitors to less relevant sub-domains as opposed to those optimized for conversion, it may damage your bottom line. For example, if a blog post about a key search term ranks higher than the main site, visitors will read the post and might not reach the desired landing page.

  1. Thematic sub-domains can cause organic search cannibalization

A while back, SEO practitioners and marketers would stuff the SERPs with various keyword rich domains and sub-domains in an attempt to monopolize them for a keyword search. Search algorithms have since changed and a similar strategy today would result in cannibalization. With a more holistic interpretation of websites by search engines, it is very unlikely that a search query would yield multiple listings from the same site.


There are situations where sub-domains are good for SEO and others where they can harm your SEO strategy.

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By | 2017-05-15T10:40:26+00:00 May 17th, 2017|Blog|0 Comments

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