I have amassed a Kindle reading wishlist that I sort through every once in a while to see if any of the books have gone on sale. I will then buy a book for about 80% off, on average. I’ve acquired hundreds of books this way, including cookbooks, books on foreign locations I’d love to visit one day, etc.; many of which I lucked into for free. Again, you just have to be patient and wait out the sales or be part of an author’s mailing list to get the alert something is being offered for free for a short time. I would buy more physical books, but due to space limitations in our tiny downtown home, I’ve had to resort to digital content. Otherwise, I would be crushed in the collapsing wake of my “to-read” pile.