The massive-growth-model of startups dictates "YOY, double revenue on a 50% cost increase. Rinse and repeat until profitable". As long as the funding holds out, this model is mathematically sound.
Uber is well on track for this from the (admitted dodgy) numbers I have seen - those being summarized here http://money.cnn.com/2017/04/14/technology/uber-financials/i.... Uber is (again, rumoured) to have doubled revenue in 2016, with a reported $6.5B net revenue, and a loss of $2.8B for ~$9.3B in costs. Double and 50% those numbers, and you get $13B, and about $12.2B, or ~$1B in profit.
Agree, but it's also not purely linear predicted growth. There are sunk costs to assist greater than linear growth. Uber without drivers surely has to be a killer business. Radio controlled by GPS "ai" "driverless" taxi with near zero customer service. Throw in electric vehicles, again cost is rapidly approaching near zero. Throw in bulk purchasing, 247 service, almost zero fuel costs and you've upended logistics. It's worth a punt to see if it can happen. One mans opinion, your mileage may vary, objects in the mirror may be closer than they appear.
Slightly off-topic… is Uber now "too big to fail" for the VCs invested in it?