Hi I would like to discuss few points on subdomains and their SEO benefits. Please provide your inputs on this so that this can be documented.

What is a Sub-domain ?
Let's say there is a domain, -http://www.abc.com. A sub domain of that would be something like -http://xyz.abc.com. So a subdomain is sort of a "new domain" but under an existing standard domain.

SEO benefits of Sub-domains.
There are quite a few benefits to using sub domains. One is that you can submit these to directories and search engines, and gain independent link's etc, which you could not do with a page such as -www.abc.com/folder/ . Also, all links from a subdomain to the main domain, are seen as 1 way inbound links, rather than internal links, which is also a big bonus. A subdomain gives you full freedom of independent domain that you can optimize while still maintaining and promoting your brand, that is the main domain.

You're right for the benefits, but there are also cons :

Each sub domain will be treated as a complete domain by SEs (more or less), so this means each sub domain will need backlinks, not only coming from you main domain.

More work while submitting to directories, even though you can image to submit more than one link at a time.

And, what you win from one part, the backlinks coming from your sub domains, you kind of lose it while linking back to them.

So the easy way is to go for folder structure, but if sud domains are active with good content, it can be good.

The principle is all sub domains should be worth a site, like a sub domain for a forum when running a big web site already, things like that.

Remember this post ?

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Another positive....Sub-domains offer the advantage of eliminating one layer. So the pages that are contained in your sub-domain are kept at a higher level than they would be in a sub-directory – and are therefore more likely to be indexed in search engines.

Regards, Stuart

You're very right, and that's what I miss the most since I had to redirect both forums.

Besides, I really think it was handy to deal with the two languages of phpBB SEO, we had the search this site option for both site in Google search

Results are a lot less accurate now, results from both forums show up when using the phpBB SEO Google search.

But, it's a matter of equilibrium in the end. All the phpBB SEO sub domain got Ranked 5 during last Google dance, and both downloads were not ranked yet before that.

By the way welcome

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yes i am with nims

sub domins always have more Advantages

point i noticed in my new subdomis

http://fr.paramegsoft.com

its got pr 3 in only 2 weeks (i creat it before last update )

so maybe when i update my forum to phpbb3

make it as subdomin

PageRank is not all.

In your case, the main domain is huge, so you could add a sub domain without problems, but remember it's a matter of equilibrium too.

If your forum is pretty much all your main domain's content, then, a sud domain won't necessarily be that good.

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Actually yea subdomains are great, because i think even till now, search engines like google still handle subdomains badly so they can be fooled sometimes in thinking that they are another website. which will work for your advantage