It's kind of a double edged sword in some ways. My Spotify subscription basically serves as a way to listen to almost anything in the background while I'm at work sitting at a desk for 8-10 hours and I don't feel like carrying a box of tapes, cds, and records back and forth, but it's nowhere near a replacement for actually owning music.
I don't think anyone besides Spotify is making much money off Spotify alone. Different labels have different deals worked out for payouts per play and from what I understand, it's really low.
A couple months ago, one of my friend's bands was on Bandcamps "Top selling new releases of the week" list with only 10 sales. I don't know just how many "new releases" get uploaded a week on Bandcamp, but I imagine it's a LOT. A whopping 10 sales doesn't scream "top new release" to me, but it says a lot about how much people just listen to free stuff and how many actually buy it.