I'm using SAN certificates (multiple domains on single cert) for that purpose. It allows me to put up to 100 domains on a single IP/certificate, which is fine f

I'm using SAN certificates (multiple domains on single cert) for that purpose. It allows me to put up to 100 domains on a single IP/certificate, which is fine for a low-traffic SaaS service. Premium clients can still get their own IP and certificate. Globalsign has even developed a special service for those cases (https://www.globalsign.com/cloud/ https://www.globalsign.com/cloud/).