Yes.
When you enter a primary domain without a subdomain we will automatically allow any subdomains.
For example, if you set your primary domain to example.com, we treat it as if you entered *.example.com. This means that if you embedded your On-Demand player on subdomain.example.com, it would work.
Note
You may not use the On-Demand player on subdomains that represent businesses that are separate and distinct from the business that purchased the subscription; it is a violation of our Terms of Service.