Are WordPress Multisites bad for SEO?
Written by Erick Olivares
WordPress multisites can be setup using completely different content and using different URL structures. SEO problems will arise if sites have duplicate content thus lowering the ranking of pages. The key is enriching websites with meaningful and valuable content for viewers.
When using Multisite, you will be obligated to choose either a subdomain (SITE.EXAMPLE.COM) or sub directory (EXAMPLE.COM/SITE) which does influence SEO. Craig Emerson tried this case study, and found that backlinks associated to the domain will be transferred to the the sub directories, but it won’t be attributed to the sub domains. Google will treat subdomains as completely new sites and will be ranked independently of each other.
Using sub directories might lead to conflicting url structures. There might be existing url paths that might try to be created and unknowingly user might try to use the same URL path. To avoid this using a sub domain might be a better choice, especially when editors and authors will have the control of adding new pages and posts.
Site admins have to be careful in including multiple detailed maps to each of the sub sites. This can be facilitated by using Yoast SEO, which will create handling sitemaps, metatags and many other features accessible and easy to manage.
The bottom line, when working on WP Multisite we need to be conscious about creating meaningful content and not so much on the SEO. Sub domains are best used if you want search crawlers to independently rank each of your sites separately and sub directories search rankings will be ranked in association with the master domain.