The most effective role of social media in creativity – according to brands, agencies and publishers

There’s an inherent tension in the creative industry about whether social media should be used solely as a media distribution platform, which comes to the fore at Cannes because of the amount of wealth social media companies have managed to ammasse, which is obvious to the naked eye when you see the huge spend on the beachfront. 
But what role, if any, does social media bring to the creative industry? Do brands see it as just a distribution tool for their creative, or is it bigger tha