In the traditional company marketing approach, marketing people concentrated on how to sell the enormous volume of products, and how to achieve specific quotas based on the human relationships with clients built up by individual salesmen. On the other hand, the main concern of today's leading companies is "intelligent marketing". Here, a "total solution-oriented business" is important, which not only involves selling products, but also gathering information from clients and making business proposals to clients. Here, by focusing particularly on marketing as a link to the market, we shall show that if there is poor interfacing with product development, this marketing strategy will not succeed. The question and topic addressed by this research was the marketing-product development interface in the context of what product strategy we should introduce in an uncertain market. The hypotheses we introduced were based on two points. First, concerning the hypothesis that "marketing information is useful in product development", the answer was negative. Next, concerning the hypothesis that "the value of marketing information varies depending on the product development process", the hypothesis was corroborated, and we found that the information required for new product development does have different requirements for each process and new product type. We found that new product development processes and new product types are intimately related to the need for acquiring information and the effect of decision-making.