Since we're on the topic of multiple companies under one (from Web Hosting Section) - what do you think of spliting up your services and making a site for each one?

Example
- 1 for shared hosting
- 1 for reseller hosting
- 1 for design/programming services?
- 1 for domain services?

Is it better to do that (split them) or just put it all under Company ABC?
Why?