The Blair Witch Project (1999)

The Blair Witch Project (1999) revolutionized horror marketing with a $60,000 budget that yielded a staggering $248 million worldwide—a 4,133x return on investment. This found-footage film, directed by Daniel Myrick and Eduardo Sanchez, used an early internet campaign to blur fiction and reality, convincing audiences the footage was genuine. Its viral strategy outperforms #10 Tangerine's guerrilla marketing by scale alone, spawning an entire subgenre of horror filmmaking. The film's influence persists; it remains the most profitable independent film ever, with a production cost 30% less than the average indie of its era.