What is the reason for the huge success of the novel, The Name of the Rose?

Umberto Eco has rightly pointed out that the success behind The Name of the Rose is a mystery. It is not possible to know the exact reason behind a book’s success or failure; one can only make wild guesses. Perhaps the time in history when it was written has proved favourable for its success. According to Mukund, the novel’s setting in the medieval past might have contributed to its success. But many novels written about the medieval past have failed to get as much success.