For decades celebrity endorsements have dominated mainstream advertising. However, these endorsements haven’t always panned out. In 1982, we saw O.J. Simpson claiming he rented cars through Hertz. Needless to say, that went sour. In 2001, Britney Spears landed an $8 million deal with Pepsi, only later to part ways because she admitted she was more of a Coca-Cola girl. In 2012, Oprah sent a....