Do low quality subdomains affect the ranking performance/quality of a root domain?

[paulissai]

Thank you so much for your response Patrick.

We have no manual actions on the main website and our MOZ spam score is 2/17. Our main website is full of original, good-quality content and we have been very careful to avoid any black hat seo strategies. We have had a professional seo expert audit our site and their feedback has been positive. In short, it seems like we have been doing everything right. We are mindful that the website might be affected by the current market for our industry, but have seen a very noticeable decline in our stats that seem to go beyond the usual market fluctuation backlash.

It is the two subdomains (e-commerce sites) that have duplicate content issues. I probably should have mentioned earlier that the decline coincided with the launch of the subdomains.

Keeping in mind that I am open to the possibility the cause of the decline could be isolated within the main website itself, I nevertheless would like to know if it is possible that subdomains can affect a root domain?

Thanks again for your detailed response - really appreciate it.

Amy

[PatrickDelehanty]

Hi Amy

Good to know you're on top of everything! In short, yes, a subdomain can affect the performance of a root domain because a subdomain is ultimately part of the root domain. I just wanted to make sure you had your bases covered in the event you were putting all of your eggs into the subdomain basket.

If you don't mind me asking, why are there two subdomains that are eCommerce with duplicate content? From that standpoint, it sounds like only one subdomain is needed. Are the two subdomains...

https://parts.caps.com.au/
https://shop.caps.com.au/

And has traffic for those subdomains declined at the same rate as the root domain, if at all?

[MattAntonino]

While I do agree it's possible for them to affect you, I want you to think about an example.

Take the keyword "blog."  By itself, it's very, very competitive.

Somehow Wordpress.com ranks #3 for blog.

They do not rank for "create a free website" which is in their homepage title but they do rank for "create a free blog" #1.

Their results are all over the place. They have a huge number of spammy, low quality subdomains. Are the inconsistencies because of the difficulty of these terms? Maybe. The spammy subdomains? Maybe.

But I can't see Wordpress.com ranking for "blog" if the subdomains could pull you down.

Take this for example (Just one LITTLE piece of the spammy pie):

http://bit.ly/1O5AzDr

[paulissai]

This post is deleted!

[paulissai]

Hi Matt-POP,

This has played on my mind as well. That is where my doubts that our issues are solely caused by our subdomains stem from.

I guess, in a sense, I am hoping that it is the subdomains because it would present a simple solution.

I am afraid of making any grand decisions, like removing the subdomians, without considering the possibility that we are doing something else wrong, but I'm yet to discover another clear cause.

[paulissai]

• Very good question Patrick!

  The parts website was developed first as our parts business is quite successful and management was looking for a more efficient way of supplying parts to our customers. The other e-commerce website was conceived shortly after and was rushed to completion - this website is the one with the most issues from an seo perspective. The marketing team did not have a significant hand in the development of these sites (you might notice they are quite different to our main website).

  To answer your question, yes, we also acknowledged that one subdomain would be better and the parts website will shortly be migrated to the main e-commerce website. We are pooling all our resources into fixing up the shop.caps.com.au site. It was only last Friday that we realised that the two new sites are actually subdomains of the root domain (why we didn't realise this earlier is beyond me) and could be a factor in why it has suffered declining rankings and traffic.

  I have read conflicting accounts on whether or not subdomains directly affect root domains - some schools of thought said no, they are ranked independently and are viewed as separate sites by Google, while others said yes or maybe. Could you perhaps provide me with a reference of where you base your view that it can/does affect the root domain?

  If the subdomains are the cause of our main site's declining performance, would it be best that we move them to a different domain or should we leave it as is and continue with our plan to migrate the parts site (this will happen regardless) and focus on fixing up the shop.caps.com.au site?

  Sorry for bombarding you with questions - this entire thing has been quite confronting and confusing considering this is my first marketing role out of college!

  Thanks

[PatrickDelehanty]

Hi Matt

While I understand what you are trying to say here, I think that Wordpress isn't the best example. Reason being - everyone uses Wordpress; according to W3C & BuiltWith, it's the CMS with the biggest market share by a long shot - here is BuiltWith's stats.

Keep in mind, for broad search terms like "blog", big name & authoritative brands are going to rank, that's just the way it is. Wordpress is associated with "blog" and topics like "content management system"; they are constantly referenced & mentioned in "best to use" lists and have been for years and will continue to be. This is also echoed in Searchmetrics 2014 Ranking Factors Studies. Brands rank for broad terms, while smaller sites rank for long tail. (Keep in mind, I understand this is a study, and we all know how those can be, especially for ranking factors)

We are talking about a big brand getting ranked for a general term - that's just the name of the search game. But again, I totally get what you're saying here.

[paulissai]

Hi Matt and Patrick,

Correct me if I'm wrong but is the general consensus that there is no definitive answer on this topic - that a subdomain's impact on a root domain is indeterminate?

Thanks

[MattAntonino]

Let's put it this way, if I owned Wordpress (or a smaller blog company) and it had two sites and one was going to get a penalty and the sites were:

http://mysite.wordpress.com

http://www.wordpress.com/mysite

I would want the subdomain penalised.  I don't think it's going to pass through to my main domain. I am nearly certain the subfolder will in 95% of cases.

@Patrick - I do agree with you but Wordpress is a very public example of tons & tons & TONS of spammy subdomains ranking just fine. I think the size of the subdomains is in proportion to their links so if a million subdomains are penalised, even on Wordpress.com, I think you'd see effect if there was going to be one.

[PatrickDelehanty]

Hi Amy

Subdomains CAN impact root domain performance, it's just a matter of how they interact. But it's odd that your sub domains are performing fine, but your root domain is seeing the impact. That just sounds odd to me.

I will have to do a little more research on your particular site to see if I find anything else. Thanks for your patience in my response on this one!