John Lanchester writes that it feels ‘newish’ to use ‘investment’ as a metaphor for having followed a TV series (LRB, 6 June). I first heard the term in 1999. I had written a dark comedy about a young journalist who reads of his own death in the personal columns and spends the movie trying to avoid, outwit or confront his fate. I was asked by a producer if I really thought my audience would be happy to make a two-hour investment in my character only for me to finish him off at the end. I could have cited movies in which exactly this sort of thing happens – Thelma and Louise, One Flew over the Cuckoo’s Nest, to name just two – but was thrown by the question. If I didn’t think the story would work, why would I have written it that way? It seemed perfectly legitimate to me that an audience should make an emotional investment in the characters, the story, the wardrobe or anything else in a movie or a TV series, just as long as they remember that the value of an investment can go down as well as up.