For the most part, you have to be a religious, educational, club/trade association, or some form of charitable entity. And it's a federal designation. In my experiences with this, I can't see any conceivable way that a marketing group who promotes entertainment could find a way to claim that status, and apply and be accepted. Maybe the fact that they are "Educating" the public about how to avoid making an investment in a crumbling sports stadium could qualify