The Blair Witch Project UNCUT Reaction!

This was grass roots marketing with a super low budget found footage movie. word of mouth helped this make a massive amount of money at the box office

You should read up on the marketing around this movie, it was crazy. The internet barely existed and they set up a realistic website with information about these "missing" filmmakers that fooled a TON of people into thinking it was all real. And since you never actually see anything in the movie that only added to the insanity. They had to put the actors on the news and stuff to show it wasn't real.