Musician, programmer, and blogger Derek Sivers writes that no matter how great your idea, it's hardly worth a dime until you prove you can build a business around it (sivers.org):

"It's so funny when I hear people being so protective of ideas. (People who want me to sign an NDA to tell me the simplest idea.)…The most brilliant idea, with no execution, is worth $20. The most brilliant idea takes great execution to be worth $20,000,000. That's why I don't want to hear people's ideas. I'm not interested until I see their execution."