The GeoTrust QuickSSL Premium SAN (Sub-Domain Only) is an economical and efficient way to secure one main domain (www.domain.com) and up to 4 additional single-level subdomains (mail.domain.com, login.domain.com, retail.domain.com, etc.). GeoTrust is one of the most recognized online security companies in the world, and you can harness the power of this brand for an unbelievable price. Plus, this certificate is true to its name, as it can be issued in only a few minutes, since it requires just basic domain validation. This certificate is best suited for small-to-medium sized businesses and start-ups that want to instantly throw their name in the hat with some of the larger players in the ecommerce industry.