Subdomains
 

I am wondering why subdomains are such a nono when submitting free sites?

Also, are they generally a bad idea or what? I am thinking of making a site that links to different webcam sites, and putting each webcam site I promote on a subdomain of the main site. Is this bad practice... a bad idea or doesn't anyone really care how I would set up a site like that. And will anyone do linktrades with subdomains?