A Leased Office Space (This is the most typical setup)
Paid shared / semi-dedicated hosting. Basic utilities. You set up cubicles and other things. Decorate yourself. This is what most people do.

Pros
- No advertising
- Very flexible
- Affordable
- You have control over most aspects of the site
- Expandable features
- Hosting reselling is an option sometimes
- Administrators deal with security/maintenance/building issues
Cons
- Still costs money
- You can't do absolutely everything you want
- Sometimes the maintenance crew upgrades and fixes utilities which is a bit disruptive
- Wacky neighbors on the same server can invite tons of people making it tough to get all of your people inside
- In that case, you need to call the building manager (hosting company) and get them to stop or shift you to another office
