Though their UI really needs some work in my opinion for it to be worth it. I subscribed specifically to listen to their exclusive podcasts, but bounced off and cancelled a month later due to it being a honestly not great experience.
It's possible that my expectations don't match the wider worlds though: my girlfriend loves Spotify and uses it for podcasts as well as music.
For me, music requires album-focused UI, and I honestly prefer having Podcasts broken out into it's own app or interface. Mixing the two just didn't feel right.
It's big but it's tied to a single service as opposed to being some huge conglomerate like microsoft or google that has it's hands into dozens of markets.