This is only anecdotal evidence.
I still like to haunt the thrift stores, used book sales, etc. and (please keep this a secret!
) buy used paper-based books. For quite a while now, I've been told by, for example, the thrift store managers, and other thrift store employees, that they have way too many books. They speak in terms, for example, of "mounds" of them (that may not be anyone's exact word, but that is the gist of what they say) in the backrooms. And the shelves "on the floor" are, many times, stuffed with used books. They get far more than they are able to sell. I could share much more.
This glut of used books seems to correspond with the surge in ebook sales about 10 years ago. That's just my impression, I have no empirical evidence to share.
The nice thing about that is that it is a buyer's market. Thrift stores, at least, have to repeatedly have sales/"specials" to get rid of more of what they have. I'm still a lover of dead-tree books and I almost grieve when I think of all of the books that they probably
throw away, simply because they have no more space for them "on the floor." But I enjoy buying them at the concomitant great prices--that is, until I try to find more space in my house to put them.
