Spotify and my own MP3 collection mostly, plus some YouTube. I'm currently a nomad, so I don't have a stereo system set up anywhere, and my CD and vinyl collection is in a storage compartment. I occasionally buy a CD to support artists I like, but then rip them to my laptop. I know they're getting nothing from my Spotify subscription, and if I have a home base with all my stuff in it again I'm going to return to physical, or so is the plan.
I'm in the same boat as
@Perun. The last couple of years I haven't had much money so I had to trim back on the CD purchasing and Spotify is much more cost effective than buying CDs. I currently don't have space in my tiny studio flat for a CD player or for a CD collection - some of my CDs are in a storage unit but most are in my old bedroom at my mother's house. Once I have a longer term job then I can move into a more spacious flat and get a CD player, reunite myself with my CDs and start buying them again.
The last couple of CDs I've bought have been at gigs when I've had the chance to meet the band and get it signed. I also know that the band get more money from it that way. These CDs are now sitting in a drawer in my office at work and I haven't actually listened to them, just ripped the MP3s off them and stored them in my digital music library. I listen to them on Spotify instead. The rest of my CDs are all stored digitally as well and I can listen to them on my laptop, but I keep that at work so I listen to the radio at home.
I wasn't buying much music and was in a total rut in terms of new bands and older stuff I had not heard.
I was in the same situation
@Niall Kielt. If I hadn't started using Spotify a few years ago then my music taste would not have changed much over the last few years. Without streaming I wouldn't be listening to Scorpions, KISS or Boston. I probably wouldn't have bothered trying out Delain, Nightwish or Epica. I doubt I'd have become a fan of Cellar Darling, Purest of Pain or Vuur. Spotify also helps me keep up with new releases as many of the new Metal songs appear in my Release Radar playlist.
Ultimately I do prefer the traditional physical music collection with the CDs, the booklet and the artwork. When my circumstances permit, I will buy CDs of my favourite bands and use Spotify for exploring new and different bands. I rarely listen to Iron Maiden on Spotify as I already own almost everything they've done.
Maybe in the future I'll use Spotify as a "try before you buy" service. If I like an album then I'll buy the CD, which is what I've done with Epica l, Alter Bridge and Delain. Hopefully the music industry can work things out with streaming services so that the artists get more money, but this is the way that things are going and artists will have to adapt to it. The music industry never really recovered from the filesharing boom at the turn of the century or whenever it was. I hope that physical music doesn't die completely though and that it can co-exist with streaming services.