That is the beauty of it. No one knows it, and it is catchy as hell. People will go, "what is that song, I love it!" And they will run and buy the Invincible album.
Or they might say what the friggin hell is that, thats not on my Number Ones album!
I see what your saying on Unbreakable, it delivers the right message, he may well go with it. But seeing as it was never released as a single I cant see it happening.