It's a totally different business model. When you purchase a license to a song on iTunes, you do so in order to be able to play the song whenever you want for a

It's a totally different business model. When you purchase a license to a song on iTunes, you do so in order to be able to play the song whenever you want for as long as you want. When you use Pandora you give the control to Pandora to choose what you listen to. You yourself admit that you spend a lot more to purchase songs as opposed to using Pandora, which tells me that purchasing tracks provides value to you that is unattainable via Pandora.