The figure I've heard quoted is that 640,000 tons of used books (not 640,000 books, 640,000 tons of books) are shredded/pulped every year for lack of finding a

The figure I've heard quoted is that 640,000 tons of used books (not 640,000 books, 640,000 tons of books) are shredded/pulped every year for lack of finding a buyer. I assume that very few of these are rare books. I think in the situation where the background rate is 640,000 tons of books being destroyed per year, the burden of proof is on the one making the claim that Amazon is destroying rare books, and doing so at a higher rate than they're being destroyed already.