When there are too many choices, there is no choice. The choices are entangled in a maze of rather confused possibilities. They go through many nebulous paths. Doubt, hesitation, indecision, become the only resolutions possible. Choosing is the anxiety of being wrong! The brand, the quality / price ratio, the aesthetics ... give confidence, but often with naivety! There is a gap between the reality of the qualities of the products and the perception of the customer. These are prejudices, illusions, a lack of knowledge ... Generally speaking, is the consumer-client able to appreciate, by sight, by touch, or even by a brief trial of operation, all the strengths and weaknesses? a lot of products? Market value dominates the use value. Marketing will discover that we must no longer confuse the consumer (the customer) and the user. The economic system only works because consumers are in the opacity of their choices. The search for technical prowess and above all market value has dominated the search for value in use.