Let us follow our reader on an ordinary morning. After leaving his bed, he probably goes to the bathroom for his morning ablutions. He then seizes the many products and utensils that contribute to this activity: soaps, powders, ointments, toothpaste, shampoo, toothbrush, razor—in short, all the products that always feature prominently above the washbasin. Each of these elements was probably the subject of careful comparisons at the time of purchase with the other variants offered by the cosmetics industry and shown on television or in the advertising pages of the print media. These comparisons concern both the prices of the variants offered by the competitors and their intrinsic properties in terms of the services they can offer. At the end of this analysis, the reader has undoubtedly chosen, for each product, to buy the variant that seemed the most attractive from the point of view of its “price/quality” ratio. From the bathroom, he then heads to the kitchen or dining room to practice a second morning activity: breakfast. There, jams, biscuits, breads, yogurts, and other pastries appear on the table, often previously toasted in a toaster or reheated in a microwave oven. In these areas too, the food and household appliance industries offer a multitude of variants, each praised for its specific quality—for example, there are more than 300 different varieties of yogurt. From the breakfast room, he finally goes to the garage to use the car that will take him to his place of work. It is not presumptuous to think that the purchase of this car, one of the most important expenses relating to the household budget, has also been the subject of special attention: which engine size to choose? Which brand? Which model? Sunroof or not? Four doors or two? Black or red? And so on.