You can collect information from them in several ways: telephone or e-mail surveys, statistical reviews of customer order history, and market trends. Ask them about their purchasing plans and projected buying behavior. Use a large pool to help generalize results. Ask them how likely they are to buy your products and tally the results.  Customers are in the best position to know the demand for a product. The danger from surveys is that they often overestimate actual demand. While a customer may show interest in your product, actually buying it is a different thing altogether. Keep in mind that conducting surveys can be expensive, difficult, and time consuming. Surveys rarely form the base of a successful demand forecast. Use this during the early stages of your product development. Find a small, isolated, area that has your targeted demographic. Roll out every stage of your marketing plan including advertising, promotion, and distribution plans. Measure product awareness, penetration, market share and total sales. Fine tune your market strategy based on the information you receive so that you will run into fewer problems when you launch your product nationally. Gather a small group of potential customers in a room and let them use your product and discuss it. The customers are usually paid a small amount for participating. Panels are similar to surveys in that they are more useful to analyze the product rather than forming the basis for a demand forecast. Find a large set of household customers to agree to participate in an ongoing study of their buying habits at grocery stores, for example. Have these customers agree to submit information such as the size of their households, their ages, their household income, and any other information you find relevant to your product. Whenever they buy groceries, their purchases are recorded and analyzed. This data can be collected when they use their store grocery card. This creates a rich database to create statistical models and see relationships in data. As with other...

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Write a summary of the previous text in Vietnamese:
Điều tra khách hàng. Sử dụng tiếp thị thử nghiệm. Mời nhóm khách hàng. Sử dụng dữ liệu bảng quét.