I’m part of the I’m sure infinitesimal and ever-shrinking portion of Amazon’s userbase who actually try to use the site to buy rare and used books. Most annoying for my experience is that they recently replaced what was in fact a best-in-class recommendation engine, which lead to a lot of my purchases, with a totally useless ad bar that displays universally terrible “related” books. There’s a world where after effectively cornering the world book market they subsequently destroy it (and they of course own and have effectively feature frozen competitors such as abebooks and bookdespository).