How do you increase sales with an already profitable company?
Answer: Expand your client-base to a market segment with more disposable income.
How do you make your favorite hobby even better?
Answer: By getting someone else to pay for it.
XOwning a web site requires you to buy two things:
You buy a domain name from a registrar company. You buy hosting space from a hosting company.
The registrar companies allows you to register for a domain name (i.e. ockhamdesign.com, etc.) and the internet address of your hosting company. A hosting company rents hard drive space on their computers to put your web site so the outside world has access to it.
Without a domain name, Step 2 doesn't happen. Without a hosting company, Steps 3-5 doesn't happen.