Optimizing subdomains

[Martin]

A site has a lot of categories, so how good is to optimize all sub domains? Will this affect the PR of the site?

[Peter]

Subdomains are treated as separate domains by the search engines so from the optimization standpoint you will have to optimize each subdomain separately i.e work on building PR and links as you might do with any domain. Subdomains are usually the best for sites which have multiple categories under one site. Adding subdomains won't have any effect on your main domain's ranking or PR.

[Rodney]

To separate different but related information on the site with large categories sub domains and sub directories are the best. They are useful when you wish to add a specific section to the website which is totally different from the content of the main page. One thing that needs to be taken care of is heavy cross linking of sub domains can get your website in trouble by google.

[sanderson]

Subdomains are usually used to seperate out parts of a site that don't go together. Like, www.blog.webhosting.uk.com for blog hosting. design.webhosting.uk.com for web design. And images.webhosting.uk.com for my images collection. Some guess folders or directories would work, but it considered to be right to give each their own subdomain.

Subdomains are also much superior than folders or directories in SEO point of view. Subdomains are considered as seperate domains. I think subdirectories are considered to be less important hence get less pr. One of the webmaster shared his experience after converting his forum form directory (domain.com/forum) to subdomain (forum.domain.com) the pr of the forum got better!

And I do agree with Rodney's point about heavy cross linking.

[Alexis]

It boils down to the question, whether subdomains should be used or not? Well, if you can afford the time and money required to create, develop and optimize each subdomain and if you think that your main domain would be too compounded by having too many categories on it, then definitely use them.