Best practice for customer base in SaaS/ASP approach

[sandrinho]

Hello everyone.

I am working about setting up an OTRS v.3.2.9 system as a SaaS (software as a service) or ASP (application service provider).
In other words, I would like several companies to use an unique OTRS system to deliver their customer services. Please note that i don't need a customer interface (i.e. customers relate with their customer services only via email and they don't need to web login to the system).
Actually i realized that using groups: each company is mapped in a group, and it can have multiple agents and queues (without seeing other companies' agents and queues).
That's great.

Then, only for statistical purposes, i need to populate the "customer base" for each company. It's not clear to me how i can "split" all the customers in different "groups".
I tried to enter the menù AdminCustomerUserGroups (after activating the customer-group association feature in the preferences), but it seems to me that it's only a separation from the Customer point-of-view.
I mean that Customers maybe see only their queues and agents in the web interface (i did not try because not interested), but agents continue to see all the customers, even the ones in different groups (for example in the AgentCustomerInformationCenter search form).
I tried also with CustomerCompany, but there is no group field at all.

Can anyone point me to some best practices to partitioning the customer base (simple customers or customer companies) and assign them to different groups?

Thank you in advance,

Sandro.