I make a point of buying any music I intend to listen to more than a couple of times. Sure I use Spotify or similar to sample things, but if there's something I plan on returning to I buy it. If I'm going to a show I buy the CD at the show (if I don't already own it) because presumably that puts the most money in the pockets of the band. The discovery aspect of the streaming internet is great, but it really isn't a revenue generator for artists. Buy their music if you listen to it. $10-$15 bucks for an album isn't much.
Ya, ya, the kids on our lawns today don't make music that's as awesome as whatever music you happened to listen to when you were 16. That's the way the world works. But if you do listen to new stuff, especially, pay for it. The non-Bieber kids today aren't making any money, either.