IMHO, domains are just there for your use in any sort of logical separation
you wish to perform...
We use them to differ between UNIX-SAP, UNIX-non-SAP, NT, DOMINO, LNOTES,
ADSM (other adsm servers), etc...
That has fit our needs...
If you have different service levels for the different clients, you may want
to use different domains to represent the different service levels...(hot,
warm, cold; gold, silver, bronze; daily, weekly, monthly; etc...)

This is one reason why I like TSM so much, you may customize it to fit your
needs.
it provides for virtually unlimited means to isolate/model/manage your
clients...

Dwight E. Cook
Software Application Engineer III
Science Applications International Corporation
509 S. Boston Ave.  Suit 220
Tulsa, Oklahoma 74103-4606
Office (918) 732-7109