Subdomain vs New Domain: Which is Better for SEO?


In case you are not interested in reading, here is the conclusion: Based on past analytics and Google updates, a subdomain on a well branded domain is better than a new domain. The subdomain will have the links and the branded domain. Plus, a subdomain will protect the site from future updates (many of the past updates have targeted less well-known domains with fewer links).

*Not in consideration is subdirectories. That is a completely different topic. 

The Case for a Subdomain over a New Domain

Pros

  • Subdomains SOMETIMES inherit and pass link/trust/quality/ranking metrics between one another (via Fishkin and Dr. Pete Myers).
    • Webmaster tools (2011) “If you add either example.com or www.example.com as a site, links from both the www and non-www versions of the domain will be categorized as internal links. We’ve also extended this idea to include other subdomains (cats.example.com or pets.example.com will also be categorized as internal links for www.example.com.)
  • Subdomain move towards one unified brand (Emphasized in Vince Update – 2009) / Panda 2013 also promoted branded results. Having a subdomain on a brand will help keep branding consistent. You won’t need new social profiles, tons more links, etc…
  • Being branded on one domain could lead to more links.

Cons

  • A subdomain could create a Long URL. By the time you get to a post, the url and main keywords in the URL are far off the domain.
  • No one is really sure how Google sees subdomains.
    • Some say it is a separate site. Cutts has only said that subdomains should be used to separate out distinct content.

What Do We Know for Sure?

  • Since links can SOMETIMES pass credibility from domain to subdomain, we know that Google could see domains and subdomains as connected content (and not separate sites as previously thought). This will be great for ranking content quickly.
  • Since content is linked – bots have the ability to bounce back and forth from domain to subdomain to domain. This will help content to be found more quickly.

Quick Synopsis:

You’ll benefit from brand, links, and the updates.

Don’t think of a subdomain as a separate site. Think of a subdomain as a closet in a house. You put things in a closet that are not necessarily what you want in the house, but they can still be seen. Same with a subdomain – it can be found, and although separate, links will pass.

The Case for a New Domain Over a Subdomain

Pros

  • If you are under scrutiny for a penalty, your site will be pulled out from the old domain and separated to a new domain.
  • Site may need a fresh start, and this is perfect.

Cons

  • A new domain is hard to rank.
  • The site will be starting completely from scratch. Also, it is not wise to move tons of content from domain to new domain with 301s. You could potentially hurt both sites.
  • New back links (besides those garnered from 301s you do bring over) will be needed.
  • Ranking will be extremely difficult because you are not competing against your legacy domain.
  • Some of the old content that you brought over may never show up in the SERPs.
  • Lack of branding has the potential to become a “networking site” if there are constant links to and from new domain to old domain. If you site is constantly interlinking – highly optimized anchor text links could hurt SEO (Panda).

Quick Synopsis:

The domain gets a fresh start, but you are building from scratch. Based on past Google Updates, it may not be the best option to have a smaller with no links. Enjoy that ranking dilemma.