blog.domain.com vs domain.com/blog

Question

Other than style, is there any significant difference between the 2, perhaps in something such as SEO?

And style-wise, is there a "standard"/good practice about it, or its just up to your personal preference?

Answer 1

No "best practice" applies.

The decision is more often dictated by administrative considerations that anything else. Some considerations might be:

Subdomain

• you can host it on an entirely different machine to the primary site
• it might make integration with the primary site more difficult (cookies, authentication, database servers, etc)
• the "blog" DNS record is the first point of control

Subdirectory

• the blogging software ideally uses the same technology as the primary site (eg php)
• the blogging software necessarily uses the same technology at the primary site (eg linux)
• the webserver is the first point of control

As far I'm aware it makes negligible difference to SEO. The difference it makes to SEO is a long debated moving target. As of 2015 there is a surge of evidence and opinion toward subdirectories.

Answer 2

Subdomains make it easier if you want to swap just the blog over to another server (since you can change the DNS for the subdomain but keep the main portion of the domain pointing to the original machine), but they can also make AJAX requests and cookies behave differently due to subdomains being seen as "different domains" in some cases.

Answer 3

blog.domain.com is interpreted as a website all on it's own where as domain.com/blog is see as a sub-page or sub-directory of the domain.com depending on how your blog is setup. I believe Google Analytics even has an option to verify and track sub-domains, which segments them as a separate site.

Site, like DIYNetwork.com and About.com utilize sub-domains, because even though it is still dependent on the parent URL it allows opportunity to house an entirely different and independent website with ease in tracking analytics.