I was in India recently. The driver said that when Uber started out, they'd give each driver Rs. 60K/mo (about $1000/mo) just to sign in for 10 hours/day, even if they did not give a single ride. Now, Uber pays by the number of rides and not a portion of the actual fares. So, for example, he said that Uber pays them Rs. 3500 for 17 rides. Most of my rides were about Rs 100 each; so Uber was taking a loss on each ride. But their system of paying by the ride is a genius idea: it removes the incentive for the driver to dick around and do a TSP around the city to drive up the fare. Now its in their interest to get the ride over with as quickly as possible, so they take the most direct route.
Edit: Sorry, "Rs" is the Indian currency, Rupee. There's about 65 Rupees to the USD.