Who Am I Listening to Today?

Everyone has on, or at least every famous person. There alter egos, a secondary or alternative personality. Celebrities such as Beyonce, Lady Gaga, Nicki Minaj, and even Garth Brooks have created alter egos in the past.  Alter egos and secret identities are the makings of good movies and tv shows, but why do so many celebrities feel the need to create different personalities? Is it just for the marketing appeal or are these alter egos true artistic expression?