Long before VHS and DVD/Blu-ray, the only way of seeing films was in a cinema or maybe on TV, if your family had some cash, 8mm edited highlight reels were also available, so there was a market back in the day for cheap photo-comics, with stills used to tell the story of a movie that perhaps wasn't playing in theatres any more. - Here's an example from Warren Publishing, issue number 2 of their 'Famous Films' mag from 1964,
The Curse of Frankenstein!
Coming Soon: Part II; The Horror of Dracula...