To find out if your idea addresses a need you need to do research. Go out and speak with vendors, distributors, potential customers and persons who run similar businesses. Also use the web to gain valuable information about competitors, similar products, trends and the market environment. Asks potential clients if they would be willing to pay for your idea and how much they would pay. After all you want to earn money with your idea. Thus you should set up a business plan to gain clarity about your business and how much money you need and how much you will make. Also a business plan is necessary to convince banks or investors if you need capital.