Multi-domain SSL
Multi domain certificates make it possible to secure up to 100 domains on the same server with a single certificate. You can mix all your different second level domains (i.e. domain.com, domain.net, and otherdomain.com).
A multi domain certificate is best for organizations that have multiple unique domains hosted on a single server. This saves time and money while providing a high level of trust and security. Compare the cost of purchasing many individual certificates to purchasing a single multi-domain certificate (which can consolidate as many as 100 domain names)