Why some domains and sub-domains have same DA, but some others don't?

[rayatarh545123]

Hi

I noticed for some blog providers in my country, which provide a sub-domian address for their blogs. the sub-domain authority is exactly as the main domain. Whereas, for some other blog providers  every subdomain has its different and lower authority.

for example "ffff.blog.ir" and "blog.ir" both have domain authority of 60. It noteworthy to mention that the "ffff.blog.ir" does not even exist!

This is while mihanblog.com and hfilm.mihanblog.com has diffrent page authority.

[dave.kudera]

Hey!

DA scores are specific to the root domain, we are not taking into account a subdomain.  So even if you search a subdomain that doesn't exist (ffff.blog.ir), DA score is still only relevant to the root domain (blog.ir) which does exist.

Page Authority on the other hand is specific to the exact page you are searching, so it makes sense that mihanblog.com and hfilm.mihanblog.com would have different page authority scores are they are separate pages.

Hope that helps, let me know if you have further questions.

[effectdigital]

Am pretty sure that Moz just unifies DA stats in some circumstances when they have no 'actual' data for the subdomain in question. Sites which are very important, which have a number of sub-domains (but not hundreds or thousands) often render different results for DA metrics. For some blog platforms (blogger is a good example, also "blogname.wordpress.com" WordPress hosted blogs) - they have thousands or hundreds of thousands of sub-domains and Moz can't index all of them

In these situations, if Moz comes across a subdomain which is well-linked across the web it will separate it out and ascribe unique values. For the rest (of which Moz holds no data), it probably just unifies the DA metric with the root domain

It's a symptom of an incomplete index of the web. That being said, no one has a complete index of the web - you have to work with what you got