AP:Young audiences turned out in droves to movie theatres around the country this weekend for a small-budget horror from a 20-year-old first-time filmmaker that began on the Internet. Backrooms, released by A24 in 3,442 locations in the U.S. and Canada, made an astonishing $81.5 million in its first three days in theatres, according to studio estimates on Sunday. And Backrooms, which was directed and co-written by YouTube creator Kane Parsons, cost only $10 million to produce.

“Backrooms,” a psychological horror flick opening this weekend, is part of a wave of breakout films from fledgling directors who honed their instincts on YouTube.

Filmmakers like Kane Parsons are getting their start on YouTube, before moving to bigger productions.