Paper prototyping will give you very quick feedback, especially if you can talk a living, breathing potential customer into being your guinea pig. In fact, with

Paper prototyping will give you very quick feedback, especially if you can talk a living, breathing potential customer into being your guinea pig. In fact, without that, it's worth a lot less. If you can't find a hot lead to sit in the driver's seat, then that might tell you something about both your idea and the market you're aiming at.