There's a difference between revenue and valuation. In this[1] example of taxi companies, valuation is 3x the revenue.
And the great potential of the company will show once they find a way to offer efficient shared transportation services at much lower prices, like [2]. If they do, they'll basically swim in money.
[1]not so great but a good start :http://www.mergernetwork.com/for-sale/nations-only-publicly-...