Domains: 1000 per account. More on request.
Hosts: No formal limit. Contact support if planning to add over 1000 per domain.
Nameserver sets: 12 per account.
Nameservers: 8 per nameserver set; 24 total per account.
Nameserver instances: Default provisioning is 1 per nameserver. Contact support for 2 or more.
DNS queries per instance: Dependent on domain configuration, features in use, and daily distribution of traffic. Usually at least 100 million/month.
API calls: 2000/hour.