I was with you upto the last sentence. Surely there are enough podcast outlets; audio is a busy segment and maybe has peaked.

No all of a sudden books, or rather long form printed delivery is in because the retail alternative is going to struggle, Amazon is too shallow in terms of customer feedback/reviews.

It is worth looking at how John Le Carre was successful. Yes, the standard PR machine at launch but how many modern authors have two video renditions so close together. TTSS & others of his works are masterpieces at more than a fiction level.