You and your sales marketing team

In this video, Alex talks about creating a strong interface with the sales and marketing team. A product manager’s priority with sales and marketing is to bring them a clear tested view of product market fit. He presents a chart of Bland’s ‘Product Death Cycle’ to explain some instances of product failure. Customers are asked what they want in a product, but when the product is improved with those specs, the customers still do not buy it. How does a product manager extract the needs of a customer to find out what they really need, instead of what they say they need?