Neither. I try to think of something I'd want to use myself.<p>That way, if it goes nowhere (which is likely), I haven't wasted my time, since I now have a useful tool.
either, since its really the person, not the idea, that matters.<p>if you're the type of person who wants to change the world, but can only come up with an idea that makes you rich, that money can be used as a tool to help you change the world.<p>if you want to get rich, even a "change-the-world" type of idea will turn inward into something that will get you rich (potentially ruining it in the process, though).
think of something that will change the world. you have the rest of your life to worry about chasing money, we can all agree that the world needs changing NOW