I'd love to know the stats for how many people listen to the entire book(or 90% of it) and then return it. I have refunded books on audible before, but it was always because I didn't like the narrator, I listen to books while driving and sometimes the narration works in the car, sometimes it really doesn't - that's when I refund and get something else, but it's always within the first hour of listening.
Furthermore, Audible only lets you return 2-3 books self-serve before you have to go through customer service. This small friction is a real impediment to abuse of the system, and I highly doubt Audible won't refuse returns if you return one every month.
I think I've returned 4-5 books total, out of 62 over the last 6 years[1]. All were because either I really didn't like the book, or the narration volume wasn't very well balanced (road noise means turning the volume up to hear the quiet parts, then getting your eardrums blasted out on the loud parts).
[1] It's hard to believe that I've spent 35+ entire days listening to audiobooks. That's nuts.
