Over the past year, movie theaters in the U.S. earned $540 million from on-screen advertising shown prior to movie screenings, according to the accounting firm Miller, Kaplan, Arase & Co. and released by the Cinema Advertising Council on Friday. The figure is up 18.5 percent from the $455.7 million earned a year earlier. CAC chief Stu Ballatt said that currently 74 percent of the total comes from national and regional advertisers, although theaters are now targeting more local advertisers, since digital production technology and digital projection now permit ads to be produced and screened relatively cheaply.