Meet the millennial YouTuber whose horror movie is beating Melania Trump at the box office

Amazon MGM Studios reportedly spent $35 million marketing Melania: Twenty Days to History, a documentary following the first lady, with $20 million shelled out in U.S. marketing alone. Yet the self-made and self-financed film Iron Lung far surpassed the Melania movie’s box office success this weekend with a bare-bones marketing scheme and a wealth of loyal subscribers.

YouTuber Mark Fischbach, better known as Markiplier, is the man behind Iron Lung, which raked in $18.19 million at the box office last weekend...