France is among the largest consumer markets for fish in Europe and its largest market for salmon, thus making it a key location for domestic and foreign sellers of fish. This report combines theory consistent demand analysis with the marketing convention of analysing purchase frequencies, to shed some light on the French fish market. It includes an estimation of a demand system of different fish types, in terms of purchase frequencies, using scanner data. The results show that consumers purchasing different types of fish are vastly heterogeneous. Furthermore, the results are used to provide an example of a marketing strategy which can increase store traffic and profits.