Or for those who want a meaningful preview of a book before buying.
Over the years, I've saved much more money by avoiding purchases of books I imagined I would like, than I've saved by buying from discount warehouses.
Libraries are one way of doing this, but for new technical books, my local Borders was a go-to place.
I will still feel bad about it. With the Borders coupons, I usually ended up spending no more than I would at Amazon, anyway. And I really like the experience of browsing. I often end up with three or four books spread out in front of me, dipping into each one, comparing their style, presentation, TOCs and indices, etc...
The ones that have put any effort into a pleasant environment, local books, reading events etc are doing better than they have in years. Remember HN are not typical of the general population when it comes to book buying or ebook reading.