At USA Domains, we don't restrict you on the number of sub-domains you can create on your account.
Sub-domains are intended for you to use solely for your website, and not to host websites for others off of your virtual server name.
If your intent is to compete with GeoCities, or other free hosts, you would need a turnkey solution with your own dedicated server. This is not feasible with a virtual server hosting account and will only lead to problems with people abusing the sub-domains and violating our Acceptable Use Policy.
We strongly suggest not giving away "free webspace" by soliciting this type of service with your sub-domains. This practice usually results in problems with no real benefit to you.
