The reason for the huge success of the novel "The Name of the Rose" remains a mystery, according to Umberto Eco, the author of the book. However, some possible reasons that have been suggested include:

• Setting: The novels setting in the medieval past might have contributed to its success. The book delves into metaphysics, theology, and medieval history, which gave the reader deep, varied, and thought-provoking material.

• Genre: "The Name of the Rose" is a different sort of novel that is quite serious and is a detective story at one level. It is a combination of mystic elements, incorporation of metaphysics, and medieval history.

Despite these possible reasons, it is not possible to know the exact reason behind a books success or failure, and one can only make wild guesses.