I am a fan of Emmylou Harris on Facebook which had a link to Emmylou Harris: Six White Cadillacs on YouTube. It’s a great song (see video below) and after watching it several times I bought the song at iTunes.
Free listening is great marketing. I had no intention to buy the CD but after listening several times to the NPR stream of it I ended up buying five more songs (six in all). That would not have happened could I not listen to them first.