You know what?
Music was originally there to share with you family, friends, and your community. It wasn't all about money. And you know what, sure a band is completely happy when someone buys their cd. And honestly, I bet most people who have that CD either go & rip it & put it on their MP3 or already have all those songs on their Ipod, downloaded from the internet. There is so much more than record sales alone that help the artist get money. Say you send your friend one song from that band, and they say 'Hey this is great'. They send it to another. And they do the same. Let's say they all live in the same area, the band comes and has a concert, there will be more people to attend it.
And besides, a lot of artists are just happy making music, because that's what they love to do.