You should read Naked Capitalism's excellent 5-part series about Uber's viability:

Part 1: http://www.nakedcapitalism.com/2016/11/can-uber-ever-deliver...

Part 2: http://www.nakedcapitalism.com/2016/12/can-uber-ever-deliver...

Part 3: http://www.nakedcapitalism.com/2016/12/can-uber-ever-deliver...

Part 4: http://www.nakedcapitalism.com/2016/12/can-uber-ever-deliver...

Part 5: http://www.nakedcapitalism.com/2016/12/can-uber-ever-deliver...