Can I create many 'sites' under one domain using subs?

Are sub-domains treated as the main domain by SEs?

[webwahm]

I want to create lots of mini sites, like when you hear of these gurus having 100s of them etc., but have them submitted individually and not be clumped together/ranked as if one massive site under the main domain.

But, do I have to buy domain names for each mini site? Or can I just add sub-domains to existing domains that I have, but wouldn't this mean the SEs treat them all as 'just one site'?

Hope that makes sense.

[mack]

I have had varying experience with this. In general terms the search engines tend to handle a sub domain as a site in it's own right. I believe it all comes down to how you interlink your mini sites. If you interlink them, then they may well be seen as one large website.

Mack.