This paper proposes a seminal model that combines heuristics and preferences to analyse decision-making processes related to the consumption of goods and services. The model has been built by recombining diferent results from economic psychology and in particular from the research programme called ecological rationality or environment-consistent rationality. With regard to heuristics and their algorithms, in addition to the well-known lexicographic rule, the importance of the heuristics of recognition, weighting and adding, sufcient satisfaction, reciprocity, default choice and imitate-the-majority heuristic in consumer behaviour is underscored. This last heuristic is complemented by the critical mass model and preliminary ideas on th...