I live in an area of SF where it is difficult to get a cab - and was previously banned from a couple cab companies because they would never show up and I would call 3 different companies to get them to pick me up.
FUCK THAT.
I never use any other cab service if I can help it.
I fly in and out of SFO several times a month - a metered cab to/from SFO and my house is $55 not including tip. Uber is flat of $65 - its more professional, includes the tip - already has my CC details and no money exchanges hands. ITS AWESOME.
Plus the drivers are typically really cool, have candies and water bottles in the cars for you.
The only complaint I have about Uber is the receipts.
I want to be able to TAG my ride with information about what project it should be billed to.
I want the little map details that you can see on the uber.com site included in the receipt.
This is the best cab services there is. I have been probably spending ~$400 a month on it - and its totally worth it.