Michael Evans argues authors hide their most interesting element in the blurb. He uses Devil's Advocate as an example: trailers revealed Al Pacino is Satan, so audiences knew what characters discovered late, creating dramatic irony that actually engaged viewers.
Also, one of the reasons too is a lot of authors actually bury the best part of their book. The most interesting part of their book is usually not in their blurb because we're all trying to be clever and hold that thing back. And the example I give people all the time is there's a movie from back in the day called Devil's Advocate and stars Al Pacino. And Al Pacino, he's a lawyer, but he's actually also Satan. He is the devil. And so when all the trailers came out for this movie and everything, they just flat out you knew that Al Pacino was the devil. The trailer gave it away. You go into the movie knowing the big twist. Al Pacino is the devil. And the characters in the movie don't find out to the last 10 minutes that they're actually working for the devil or in a romantic relationship with Satan kind of thing. But it's that experience of you knowing and the characters not knowing that make it really interesting.
