Search engine optimization is an evolving discipline and many people particularly upcoming SEO professionals keep on asking some questions regarding how links and content should be structured for optimal search engine optimization with respect to subdomains, subfolders, 301 redirects and rel canonical. The discussion below looks at these questions in great detail and how to address them as and when they occur.
Should I Opt for Subdomains or Subfolders When Putting Content for My Site?
Subdomains have been preferred because of the fact that they are less technical and you do not need your development or engineer staff to get involved in putting them up. Search engines may associate the content that is on your separate subdomain with the main domain and this may mean all the user data signals and links as well as the ranking signals may benefit both the subdomain and the main domain. However, this is still a probabilistic event.
Previous tests done by first putting content on the subdomain and thereafter moving it to the main domain (subfolder) has shown positive results in terms of ranking improvements. However, there are verifiable reports of a drastic drop in search engine ranking when content from the main domain was moved to the subfolders.
The bottom line here is not to put content in a subdomain, but rather on subfolders in the main route domain. This is a safe way to maximize your SEO potential and benefit.
When Moving Content from a Separate Site to My Main Domain, Should I Use 301 Redirect or Rel Canonical?
If you have content on a number of sites and you want to move some of it to your main or central website so that it can be interpreted as coming from the main site, you have the option of using the cross-domain rel=canonical or the 301 redirect.
The only difference is that with the 301 redirect, the visitors or traffic will be redirected to the new or main site with no option to visit the old site. On the other hand, rel canonical gives you a taste of both worlds where you have the option of going back to the old site or proceeding to the new.
What you use between the two is a matter of branding and user experience, but doesn’t have SEO ranking effect.
Does Multiple Websites Linking to My Main Site Help or Damage SEO?
Using different sites you own and using them to link back to your main site in the hope of improving your SEO on the main site, may prove futile. This is because doing so creates a barrier that undermines the full link equity to be passed onto your brand including social signals and user data signals.
The best approach would be to 301-redirect all the sub-sites to your main site so that you can concentrate on building one brand. Branding is so powerful online and you may not benefit much by keeping a collection of corollary sites.