We show that the simple fact that a monopolist sells a good in units which are indivisible may well induce him to select a quality for his product which is not the highest one, even if no cost of any sort is attached to quality improvement. ∗CORE, université catholique de Louvain †CEREC, Facultés universitaires Saint-Louis & CORE, université catholique de Louvain 1. Even leaving aside price dis...