Hitchcock wasn’t only a master of moviemaking, he was pioneer of movie marketing. Psycho was a low budget film ($800K) that could have easily tanked.
When Hitchcock finished the movie, the studio refused to premiere it. Which forced him to come up with his own marketing strategy. He filmed this message to moviehouse managers across the country to show them how to “sell” Psycho, which (brilliantly) advised them to forbid anyone entrance after the movie started. This resulted in long lines of ticket-holders outside theaters and drive-ins, jittery with anticipation, which translated into great WOM, much harder to achieve when social media required social contact. Psycho became one of the hit movies of 1960 and was nominated for an Oscar.