Are they good or bad, I cant recall. I would love to hear others thoughts on this....
Like for instance with forums, say your site isn't meant to be all forums (or even if it is) should use a sub domain for your boards like "forum.xyzabc.com"?
I'm thinking it cant hurt since well since it is a more professional organized way to run a site...
Then again I could be wrong
I will eagerly wait your replies
-edit
I am seeing from my own research that many times a SE will see a sub domain as a completely independent site if you structure it that way. This being said the argument of if your site is going to aesthetically stay the same you should just use sub directories but if your site is going to change use sub domains. Now A sub domain is basically just a sub folder on your main directory with a cgi-bin for example. since you can access and sub domain by just using the folder (e.g. sub.domain.com/ can be found at domain.com/sub/).
So how does one decide to implement sub domains and what SEO benefits would they receive by doing it that way. I still think it would be a good way to organize your site.
Interesting discussion
http://www.searchengineforums.com/ap...d::1167440066/