 Because he was able to release these music videos at a time when MTV was the coolest place that you could have your music videos featured. And the videos served as previews for the film. And then the film served as a preview for the Purple Rain tour. And it all just kind of worked in coordination where suddenly he was dominating. He had the number one song, the number one album, and then the number one film in America all at the same time, which is really incredible.