Before you make a light bulb, you need to have people who require light. If you grow something in your fields that you need to sell, you need people to eat them. For every product that exists out there, there is a consumer. The only way you will know how to develop your product and how to sell it is by realizing your target market.
Every product has a market. It targets certain people with certain tastes and lifestyles. Thats where research comes in. You need to show investors the consumers that exist out there. This is usually done in the early stages of production, when you dont have a finished product and you are looking for venture capitalists. You need to show them numbers backed by assumptions that you are making with discussions about them. All of this research needs to be done by you. It need not be lengthy or expensive. The best way to conduct this research is by telemarketing or sending out questionnaires in the mail. By sending this information to the right demographic, you can attain the right numbers.
The second thing that you need to include in your research is customer needs. The basis of business is supply and demand. Without knowing who wants your product and in what quantity, you are committing yourself to a foolish act. These days the average consumer has a very short attention span. For them to look at a product with even remote interest, the product has to serve their need or desire. For that to happen the product has to have all those qualities that the consumer is looking for. The only way you can find that out is by asking them before hand.