We do not allow the creation of sub or addon Domains. The system is strictly: 1 Domain per IP. If we did not do it this way it would lead to overselling, which in itself causes a variety of problems, as well as us not being able to provide you with the security for your pbn that we do. We randomely limit the total number of domains that can be put upon any IP and this would not be doable anymore if we allowed addon domains.