BusinessWeek offers up this special report on Passion for Business.
"Everyone feels passionate about something. But invariably, some enthusiasts have the proverbial eureka moment, becoming convinced that they have a million-dollar business idea on their hands. So how can you tell whether or not your particular passion has what it takes to make it out of your basement and into the big leagues?"
STEP BACK. (Gee, sounds amazingly similar to Discipline VI - Step Back) "You've got to determine first if there's a market for it, then determine how much profit is in it."
FORGET UNDERCUTTING. "The question is: Is there something distinctly different between your idea and what's already available out in the market?" (Forget price as a differentiator.)
GOTTA LOVE INVENTORY. Do some thorough market research. But beware: Although seemingly straightforward, this is the stage where many passionate hobbyists fail. Aside from your passion, do you have any real interest in the business side of things? If not, you'll take something you really enjoy and mix it with something you really hate.
KEEPING THE SPARK. Doing what you're passionate about makes a big difference, but it's not just about your passion. The operative word here is 'doing it as a business. The trick is to do that while maintaining your passion.