Author unknown. Attributed to P.T. Barnum in Plays and Players (1957), Volumes 5-6, stating "That great showman, Barnum, once said that there was no such thing as bad publicity". But see Constance Hope, Publicity is Broccoli (1941), p. 17: "The press agent is the fellow who believes that there is no such thing as bad publicity". See also Charles Clay Doyle, Wolfgang Mieder, Fred R. Shapiro, eds., The Dictionary of Modern Proverbs (2012), p. 253, citing Clifton Fadiman, "The Reviewing Business", https://en.wikiquote.org/wiki/Publicity