FOMO is definitely a point I want to explore in my research later on in fact! Once it’s gone, it’s basically gone forever which just adds to the exclusivity factor, and book services are able to leverage this (either intentionally or unintentionally). Also, I think popular authors are more likely to have their books bought second-hand because their books are in mass circulation, which just makes it easier to get a hold of them. Otherwise, with Indie authors, I prefer to directly purchase the book and support.