I think it's important to realize just how rare a position Brandon Sanderson is in, really. Publishing and the literary scene outside of the major publishers has always been people using the little money they make to try and keep it alive outside of the dominant system that's creeping towards a monopoly in NA. Most stuff just doesn't have the huge marketing capability that Sanderson does and usually fails. Frankly, most authors are barely able to make a living doing it. Sanderson is far from the only person trying to help authors in publishing, but his 0.1% level financial success in publishing likely means he can accept much more risk than even more well known authors.

That said, I do find it kind of ironic that he made a secret deal with Spotify, which has its own pitiful history of payouts to artists. But atleast free accounts get access to the books as well.