If you are looking for theory or for technical analysis of film, this is not the place. If your interest, instead, is insight into the thinking that goes into making (mostly mainstream) films this is an excellent starting point. Boorstin doesn't write like a movie critic or a professor of film; he writes like a very knowledgable and reflective craftsman who has insider experience on filmmaking and has been able to capture that experience into a series of analytic perspectives on the nature of "movies that work."
He breaks his analysis of the "working of movies" down into three perspectives that amount to the various levels at which the film needs to operate on or captivate its audience. A movie that "works" has to work on all three levels, though it may emphasize one over the others. First, it should appeal to the "voyeur" in the audience. We watch movies because we want to see, and a movie works at a voyeuristic level when it shows us something that we can both believe and be interested in. That sounds straightforward enough, but the voyeuristic perspective allows him to go into the "why" behind a wide range of cinematic techniques, and to introduce quite a bit of the vocabulary you'd find in another introduction to film but might not see why it was so important. Secondly, the film has to work at a "vicarious" level: we have to care about the characters in the film, and what they do has to be emotionally true. Under this heading Boorstin is able to discuss a range of topics, from Kuleshov's psychology experiments with film montage to what makes a film soundtrack work. The third level is the "visceral": films can work, not only because they are intriguing or make us feel something for the characters, but also because they make us feel something period. The rise of horror cinema is directly connected to this longing for a visceral experience: we don't just want to care about someone who is potentially being harmed but we want to feel their fear along with them. The book goes on to discuss combinations between these, the differences between narratives and films of other forms, and the difference between mainstream Hollywood cinema and avant garde or foreign cinema.
My only quibble with the book is that he doesn't address a fourth level at which films work -- maybe because it's hard to come up with a "V" word for what might be called the "reflective dimension" of film, and I believe that a discussion of this dimension would complement his other discussions and allow him to introduce in an unpretentious and insider fashion themes that are the subject of what film theorists call "ideology." Every film, at some level, has a theme -- has to have something it is "about" and this is a level that is not only of interest to film theorists but also to filmmakers. Sidney Lumet's wonderful "Making Movies" discusses this at length. For a film to work it has to have a theme and it has to somehow make sense of that theme. In some films, and not only foreign or avant-garde films, this "thematic" or "reflective" dimension is the dominant one. Take the success of the "Matrix" for example -- what makes it stunning is not only its superb visuals (voyeuristic level) or its strong narrative (such that we vicariously connect with Neo) or its tense mood (such that we have a visceral experience), but also that it forces us to think, raising interesting questions and posing tentative answers to those questions.
In the end, though, this is merely a quibble with what is still a very worthwhile book that I am glad I encountered. While the style is personal and the ideas are to some degree idiosyncratic to the author, it is a rare book that offers so much information and insight and is such an enjoyable read. (I would compare this book to other remarkable and insightful works by working filmmakers such as Lumet's Making Movies and Walter Murch's In the Blink of the Eye -- and if I had to choose which one to recommend of these three I would say that Boorstin's book is more comprehensive and can likely teach more about the nature of film and filmmaking than the others.)