Language code as sub domain

Site's language code as sub domain vs. root directory.

[jonter]

I'm running a site available in some 30 languages and approximately 20.000 visits per day. English main page has got PR 5.

Currently, the URL format is http://www.example.com/lang/what/ever.html where lang is en, de, es etc.

Now I'm thinking about going Wikipedia stylee and reorganise URLs as follow: http://lang.example.com/what/ever.html

My concerns are user friendliness and SEO. I would be pleased if anyone could share their experience or opinions.

Thanks,
Jon

[edited by: encyclo at 3:24 pm (utc) on May 29, 2008]
[edit reason] switched to example.com [/edit]

[encyclo]

Any theoretical advantage would be counter-balanced by the fact that you would be redirecting large swathes of your existing website to new URLs. If your site is doing well and the pages are indexed, then you should stick to the existing URL structure.

[jonter]

Thanks encyclo. You're absolutely right. A whole lot of traffic would need redirection, at least the first few months. They would be done at .htaccess level using Apache's mod_rewrite module.

One of the reasons why we're looking at this is because of the way Google site links are generated. At the moment they are absolutely pointless as it generates a mess of links to different pages in different languages.

Apart from that, if there are no other benefits in changing URL format, I suppose it's better to not touch anything.

Any other opinions are more than welcome!

Jon