The Commercial License: Is it a good long-term investment?

Hello everyone,

Everyone knows that if you put in thousands of dollars for a solid
college education, you'll reap the benefits later on. Is it also true
for the FAA commercial license? If I put in the extra money to get a
commercial license, can recoup that money (and them some) by starting
an air chartering service? Is the air chartering industry profitable?
I have a great day job and would like to keep it. I'm willing to spend
evenings and weekends flying an air charter, but I don't know if I'll
go bankrupt. What are your two cents?