> The 15 hour monthly limit might begin to act as pressure to keep audio books length under 15 hours. Some in sci-fi can exceed that limit now.

When I read this I instantly went to review my collection. To my surprise, approximately half, were under 15 hours. I would have thought for sure none I've listened to were under 15 hours, but like I said, half were.

In my opinion, Spotify audiobooks will fail because of limits like this. When my listening was at its peak, I would crush multiple books a month (at 1x even). If I were a customer, the first time I hit that limit would be the last day I was a customer.