I am shocked to find out that no one in in this thread mentioned Scribd.

Scribd is the go to place for audiobooks, it is the only major subscription service I regularly pay.

Audible is horrible, their business model sucks, and what sucks even more is their scummy marketing.

Scribd is basically the Netflix for books, and I honestly love it and cannot recommend it enough.

I do think it has way more potential to become something if it integrated with other services even better, but I guess working with publishers is not easy...