I have difficulty believing that Neflix is paying up to $4 per streamed movie. There's no reason to even offer a movie to stream if it costs that much in comparison to your regular membership fees... I'm calling bull on this one...
I don't think they meant it costs $4 to stream a movie to just a single person, but $4 to have the rights per movie per day and thousands can stream that same movie, so if it's a popular movie then it comes down to pennies per person.