Tons of subdomains little content

[asphalt]

I am putting together a blogger style site each user will get his own subdomain, like username.thisdomain.com. This could be thousands of people, most will put up little to no content...but some will have a fair amount.
What is everyone's thoughts?
WIll this be a problem?

I am not sure how search engines deal with subdomains I always thought it was as a new domain?

Any suggestions or concerns I should be on the look out for would be appreciated.

[James]

I think they just see it the same as domain.com/username
Don't quote me on that, tho.

[asphalt]

James Thanks,
I did a search "Google treat sub domains", and found a lot of information. Everything I read seemed to point to the fact that they are treated as different sites.

If this is the case how do I setup a linking strategy. I will probably for a period of time have links going to each new blog and then also link back to the home site. I assume this won't cause too much problems...