(Studio Briefing) Moviegoers may be complaining louder than ever about those in-theater ads that run before the trailers, but they are becoming an ever-growing source of revenue for exhibitors, according to a study by ZenithOptimedia and reported in today's (Tuesday) USA Today. According to the study, revenue from those ads rose 18 percent this year to $400 million and is expected to rise about 15 percent each year through 2008.