La Ville managed a successful business with clients from powerful parts of society.
She performed various alleged magical acts for money, and her business has been compared to that of La Voisin, whose net of occultists was dissolved in 1679.
Among her clients were Madame de Grancey, an acquaintance of Philippe II, Duke of Orléans, and the marquis de Feuquieres, previously the client of La Voisin, who reportedly hired her to summon a demon by the name of Prince Babel.
Already in 1696, six years before, a professional female fortune teller had been arrested for black magic, although the case was never brought to trial since it was discovered that the Duke of Chartres and the marquis de Feuquieres were among her clients.
[5] Because of this, d'Argenson recommended that the case of Marie-Anne de La Ville and her organisation of her colleagues were not to be brought to trial, and that instead, the arrested should be imprisoned without a trial by a lettre de cachet, in the same manner as the accused in the Poison Affair eventually had.