@Jeroen: very well explanation, thank you very much.
The company I work for rented a VPS through digitalocean.com, and DO don't yet provide more than 1 IP per droplet (vps). The company have few domains with few services, but, different business types and different associates. They can't really be called a company since I'm working for one of the associates but trying to serve all their requirements). Ofcourse I can still pick up a semi random domain name and make it primary for services that don't support SNI, much like shared hosting companies, but that means I'll have to walk with every non-techie user on how to configure their mail client, their iPhone, their Android, ... I've seen old mobile devices (like Nokia 5800) showing warnings about the certificate every time it tries to sync mail, even if you tell it to ignore that warning and never bother with it again; but it keep showing it either way, which is very annoying on every sync. Jeroen's reply pretty much sums up the reasons behind the need for different SSL certificates on a single IP. Regards.
