my reading of that book was that Deleuze was suggesting it as a way to fight capitalist control over thought and behavior -- i.e. if you think and behave in a way that's non-rational, you can escape the capitalist mind prison. idk though, it's a very hard book to read because it takes post-structuralism farther than the post-structuralists did and adopts his own thesis. so it's entirely possible I'm misreading him. he expands, in a more elucidating manner, in Societies of Control, so it's worth reading that as context for the book.