I think that's what it's called. Knopf does it with all their hardcovers, how the edges are cut rough so they don't all line up. I hate it. It makes it harder to turn the pages and it's aesthetically unappealing.
Don't get me wrong, it's not going to stop me from buying the book. But I just don't see how anyone would prefer rough-cut instead of making it all even.
I like my books rough-cut only if they're a bodice-ripping, swashbuckling historical romantic suspense novel. Makes me feel part of the action.
In other words: I do like it if it suits the story, but I wouldn't want it on every novel. I'm a little superficial like that, I bought IN THE WOODS because I loved the blackened edges of the paper (I don't believe the US edition was like this). Luckily I also enjoyed the words written on it.