Do social media apps have a future?

Not a day goes by without hearing about yet another new social media app, with a revenue model built around advertising.

* Who thinks that this is a sustainable business model? * What other ways are there to monetise these apps? * Will there be shake up and consolidation in the market? Can all these startups survive? * Is social media just a fad that will get left behind if people decide it's just not real enough?