The most successful one-man business is not in software. I know of a successful mediator. He charges $18000 to $20000 per day and has always been booked for the last 20 years.
http://www.wqsadr.com/randallwwulfffeescheduleandpolicies.ht...
http://www.wqsadr.com/randallwwulfffeescheduleandpolicies.ht...
Just a side note, most mediators are former lawyers. After many years of practice, they seek a better way to resolve conflicts. The pay isn't bad either.
One more thing. Randy is actually one of the best mediators in the world. After the 9/11 attacks in New York, Randy was called in to mediate and arbitrate the case with the insurance companies and tenants. After 2 years, they were able to come to an agreement and the resulting funds allowed for the area to be rebuilt.