I'm as far from SFO as you can get in SF and my Mercedes car service to the airport is $45, and $20 for anywhere within the city.
With Uber, I have the convenience of the CC handling, the receipts and the power of many more cars available to me than I would if I was only calling one guy, like I used to.
Uber takes 20% of the sale, the car company then splits the 80% remainder at some % level. The last driver I had mentioned that he was trying to hire three more drivers. He has the cars - but has a hard time trying to find drivers.
He said that the drivers can make between 3 and 4 thousand per month. Which is great. I recommended a friend who has a degree in cartography but cant find a job. 4K/month is a great salary for anyone struggling in this economy.
The iphone app is fantastic. Call the car, see it on the map, get a txt when they arrive - or the driver calls if he needs better directions.
You don't get that with a private car.
Although - There is CERTAINLY a market for an open version of the Uber app.
Imagine the open-cab concept - works just like Uber - but drivers register their availability in the app and users make pickup requests just the same. The drivers select the client they are going to get - and the app manages the queues.
Totally doable.