Subdomains vs. Subfolders for unique categories & topics

[grapevinemktg]

Hello,

We are in the process of redesigning and migrating 5 previously separate websites (all different niche topics, including dining, entertainment, retail, real estate, etc.) under one umbrella site for the property in which they exist. From the property homepage, you will now be able to access all of the individual category sites within.

As each niche microsite will be focused on a different topic, I am wondering whether it is best for SEO that we use subdomains such as category.mainsite.com or subfolders mainsite.com/category.

I have seen it done both ways on large corporate sites (ie: Ikea uses subdomains for different country sites, and Apple uses subfolders), so I am wondering what makes the most sense for this particular umbrella site.

Any help is greatly appreciated.

Thanks, Melissa

[DavidKauzlaric]

Definitely use subfolders!

By using your subfolders you pass all link juice and PR to the main domain which is mainsite.com. If you have say 10 subdomains, you are splitting the authority/link-juice/PR.

I know there are others who say Google passes the juice between a domain and subdomain, and it does pass some, but not all.

You cannot go wrong using subfolders. You build up one main domain, it's clean, user-friendly, etc...

SUBFOLDERS!

[StalkerB]

Yeah, I'm a subfolders kind of guy too, but here's SEOmoz weighing in on the subject of microsites and talking about the same sort of question you are - http://www.seomoz.org/blog/understanding-root-domains-subdomains-vs-subfolders-microsites

[danielkamen]

Its a no questions asked answer- SUBFOLDERS-  by creating subdomains it's like saying your a separate entity and by doing that you will not be sharing all the value from the main domain and all the domains combined ie. pagerank, pages indexed, links, etc.