Having clearly articulated your @ha Idea, evaluated the likely demand for it and described the exact need that it fulfills you now need to re-describe your @ha Idea (in a sentence or more) and re-evaluate and re-describe the exact need(s) it fulfills.
Do the above 3 times over on 3 separate days. By the end of this exercise you should not only have a clearer description and vision for your @ha Idea but you will also most definitely have a more thorough and multi-perspective view of the exact need(s) that your @ha Idea fulfills.
Tip: Involve friends and family as much as possible in this exercise. And listen openly and neutrally to their feedback. Outside perspectives are critical while honing your @ha Idea and need down again & again & again. You can also use Web 2.0 tools to extend the universe of people to test your idea against.