The development of commercial sound cinema had proceeded in fits and starts before "The Jazz Singer", and the film's success did not change things overnight. Influential gossip columnist Louella Parsons reaction to "The Jazz Singer" was badly off the mark: "I have no fear that the screeching sound film will ever disturb our theaters," while MGM head of production Irving Thalberg called the film "a good gimmick, but that's all it was." Not until May 1928 did the group of four big studios (PDC had dropped out of the alliance), along with United Artists and others, sign with ERPI for conversion of production facilities and theaters for sound film. It was a daunting commitment; revamping a single theater cost as much as $15,000 (the equivalent of $220,000 in 2019), and there were more than 20,000 movie theaters in the United States. By 1930, only half of the theaters had been wired for sound.