Long time Aubible member here but now I also use
http://www.Podiobooks.com because I grew weary of the hoops from Audible and it's ever bloating file sizes and increasing inflexibility. Too old, too worn out to keep on that treadmill. Podiobooks is not typical mainstream but I find a lot of fun content there. I discovered The Leviathan Chronicles and some other SF titles which were lots of fun.
I still like Audible's offerings but every time I turn around there are issues, limits and frustrations. Pretty much all of which came under Amazon's ownship of Audible.