Personal anecdote, a family friend sells Usenet access. Seems to be doing very well. Probably the same things that make him successful is the same thing that made my father's business (commercial roofer) so profitable. 1) Unsexy markets. They don't attract competition. 2) Be your own salesperson/secretary/accountant/marketer/janitor/2-3 (cable/roof) monkeys. You don't have to hire bodies if you don't want to and you'll often work harder when it is your bacon on the line.