At some point, though, every company that wants a sustainable business model needs to make money "on average" on the sum of all items (units of service, e.g. rides) sold. Uber being a local business should be able to do this progressively as its business matures in each city. However, if it is true that they are not profitable in their mature US market where by some accounts they enjoy >80% market share, that implies some substantial flaws in their model. Subsidizing rides in Asia or some smaller city in Europe is ok to gain growth, subsidizing rides in New York or San Francisco is worrying. And autonomous driving implies a completely different business model and economics (driven by the "who owns the car fleet" discussion).