I use two filters: 1. I only buy (and read) a book that is at least 10 years old. For me, 10 years is enough for other people to figure out if a book is worth

I use two filters: 1. I only buy (and read) a book that is at least 10 years old. For me, 10 years is enough for other people to figure out if a book is worth to read. 95% of all books that are today's bestsellers turn out not to age well. Because none of the books are new, I can usually buy them used. 2. I'm only buying it if I'm pretty sure I'm going to read it. I always read the digital preview and sometimes (if available) I download the digital version which I read for a while. I want to know if I'm going to read the book before buying it.