Two central transformations occurred in the second decade of twenty-first century. The first is a whole new level of access to information about peoples’ habits. This is the ‘big data’ revolution: never before had it been possible to gather so much information about so many people, with such accuracy – specially gathered by huge online service providers such as Facebook, Google or Amazon, which record each of the action of their users. Thus, while marketing strategists or political campaigns have always sought to know the preferences of particular segments of the population, big data makes possible a truly high-resolution profiling of behaviours, which reflects the habits of specific individuals, and not only of demographic groups or certain geographical areas.