can't remember where I heard this but the advice was basically this: When pitching your idea, and generating excitement, ask for money (or a commitment) on the spot. There's a big difference between saying you'd pay for something, and paying for something.

The flip side is that sometimes it takes awhile to build the perception of value, hence free trials/freemium models. Get people hooked, then ask for $.

There are many ways to be successful (and even more ways to be unsuccessful).