Pandora

I love Pandora.com, and it's free. This is a perfect example of something I would pay a decent amount for, but they don't charge me anything. Looking at a basic supply and demand curve,

you can see that in the event we were at equilibrium, the consumer and producer surplus would be split evenly between me and Pandora. In this case however Pandora is willing to provide an unlimited supply for $0 so both the consumer and producer surplus shaded portions are going to me, and it's all consumer surplus! Bad news is that Pandora likely knows this, and they will be attempting to capture some producer surplus or "monetize" their product as they call it. For now though I'm going to enjoy the consumer surplus and free tunes while they last.