Read an interesting article today about domain purchasing and the amount of money you can make doing it. Essentially there are people that purchase URLs that they think people will type in and then run Google AdSense or something similar on it.
What is also big business is buying misspellings of other company’s domains. I have personally seen this with a few schools’ web sites where another company has purchased a very similar version of the school URL. This is big business, and it may be costing you leads.
When purchasing your domain, it may be worth buying other versions and misspellings of it to make sure you aren’t helping somebody else get rich.