Numerous works have illustrated the benefits of including quality labels on food products. They provide products, brands and territories with added value. The increase in quality signs nevertheless leads to market congestion resulting from both the juxtaposition of these signs and the overlap created on the same product. It is not uncommon to see a product carrying a commercial brand, a quality sign and a geographical origin. Combining a brand and a quality sign is a relatively common practice, but we are beginning to notice a significant increase in the number of products carrying two or even three quality signs (brand and origin, organic and fair trade, organic and origin, fair trade and origin). Recent work has shown that, in some cases, this practice of combining signs is not synonymous with an improved product valuation. In this paper, based on the contributions of cognitive psychology and experimental economics, we endeavour to demonstrate the role of cognitive coherence between the different labels in consumer choices. This research is based on two food products carrying: i) an organic label and a fair trade label, and ii) a brand and a geographical origin. Results show that the additional impact of the second label is very limited and less beneficial than the sum of added values of each label, and that it may lead to a negative value in the case of perceived incongruity between the two elements.