Making Money As An Open Source Game Developer?

Fastball asks: "I have a couple ideas for some web-based games that I'd like to develop. I'm an avid Linux, Perl, Apache, and MySQL user, and I believe in the GPL. However, I'm trying to figure out how I can develop these games as open source and still make a buck. It would be rewarding to produce them without seeing a profit, but I'd like to make enough money to get a company going and quit my current, uninspiring job. Can I get there via open source, would I be more profitable going closed source, or should I forget about make money altogether?"