Neon's promotional teasers for 'Longlegs' have gone viral for their creepy, reality-bending qualities. What other horror movies have successfully sold scares? In the spring of 1999, word started to spread among college campuses in America about some missing students. Leaflets were handed out, stories were planted in newspapers and rumours peppered through chat forums.

An official website was updated with theories, images of the students and mythology about what they had last set out to document: a haunting local legend known as the Blair Witch. None of this was real, of course. It was an extremely clever marketing campaign for the found footage movie , famously made on a shoestring budget of $60,000 (€55,429) and garnering $248.

6 million (€229.6m) in return. This innovative early use of the internet to create a viral campaign of intrigue, blurring the lines between fiction and reality, changed how movies were marketed forever.

While there have been many similarly creative (if less culturally defining) movie campaigns in the years since, it’s undoubtedly become much harder to craft the same level of hype without giving too much away. Trailers tend to be over-stuffed and social media is awash with spoilers that are quickly followed by the next big thing, creating a brain-frazzled feeling of content overwhelm that makes it difficult to sustain curiosity about anything for more than five minutes. But then along came - Oz Perkins’ horror thriller about an FBI agent named L.