Technically speaking, anything inserted into the pages near the spine is not good for the spine. But that is just on a pure theoretical basis. In reality, a standard thin (paper) bookmark will not cause harm. I agree that the thick bookmarks are stupid not only because they can harm the book, but also because they fall out too easily.

If you do that in our house, Susan will cut your nuts off. Me: if it is a paperback, I don't care.

However, she uses paperclips as her bookmarks as they are far less prone to falling out. When I point out that they mark the pages akin to the marking left by folding overs pages, she doesn't have a strong response. Oh well.

Cramming something deep into the spine of a book isn't good for it, and this design, by using the books weight, guarantees that.

But on the other hand, that lamp is really only designed for paperbacks. For larger books you're going to start facing a tipping problem; either of the lamp because the book is heavy or of the book sliding off one side or the other when you are near the start or end of the book. But who really cares about keeping a mass market paperback in good condition (not even most libraries particularly care about the lifespan of them).

I wonder if there is a floor lamp for larger books?

I don't see the real potential for damage given the couple of days it takes to read your average paperback. In fact having a nice safe place to stash the book is great. I just lost the copy of "Team of Rivals: The Political Genius of Abraham Lincoln" I was reading when my psychotic dog ripped it to shreds all over my bedroom. I guess he must be a democrat.

The answer is post-it notes. Did you know that they were originally invented as bookmarks for people in choirs? The guy sang at his church, and if you hold the book up while you sing, your bookmarks and notes fall out. He was pleasantly surprised to find his sticky disposable bookmark notes were useful at the office.

Alex is right, per usual, though I'm a particular stickler for keeping any type of book in good shape.

Well, sort of true according to Snopes.

Interesting, I didn't know about the Secretarial Test.

That was actually the first story I had heard about Post Its. That was what I was searching for when I got the Snopes story.

A perfect combination of form and function.

A Mousetrap Coffee Table Uses Its Victims For Fuel

my thought being, if you have enough mice in your house to warrant that...you probably should be spending the funds on an exterminator instead of a fancy coffee table.

but its an interesting idea none the less.

I suppose if you scaled it up a bit it could also work with cats and then Leo would purchase one....