The problem is that Uber loses money on every ride, so they'll have to raise their rates as soon as they stop being subsidized by VCs -- unless they have self-driving taxis by then.
Answer is they provide great rates for passengers - see all of the anecdotal evidence here - and great pay for drivers.
It literally is "too good to be true."
It's just an app--with a $20B valuation and about as much in free cash.