Bell's Pyramid of Plot

I've been reading Plot & Structure by James Scott Bell and it is an excellent resource. Not only does he give you ways to ways to generate plot ideas. He shows you want to do with them. You've got to narrow them down and the way to do it is with the Bell Pyramid.

There are three layers to the Bell Pyramid. We'll start at the base and work to the top.

Passion: A novel takes a long time to write, so you must be passionate about the plot you choose to write about. Rejections abound in the publishing world and many times it is because the work presented is "cookie cutter" work. Writers will follow the crowd and write what is selling instead of writing the book in their heart. You must feel passion about your plot to sustain your writing through the lenth of time it takes to write it.

Potential: You have to consider the possible reach of your plot idea to an audience. The way to do that is to put yourself in the shoes of an invester. Would you want to invest thousands of dollars in a book about cleaning a fish? Hhhmmm. You don't need to write to the largest possible audience, but you do need to focus on a specific audience and write a passionate story to that audience. You want to write romance? What kind? Historical, suspence, contemporary, etc... It is not a rule, but a guideline as you write what you are really passionate about.

Precision: You've found what your passionate about and think the potential is there for a readership following. Now you must trim away anything that is not in line with that potential. If you are writing for suspense, don't get distracted from that focus. You don't want anything to distract from the potential.

How do you decide which idea is the one you run with?