It’s the indicator of when the last reader ended the book – Dog-eared the page and never picked it up again. Greater insight than any Amazon review can give you.
I started reading a book today, eye-rolled at the introduction and then was completely vindicated by seeing page 1 of chapter 1 dog-eared.
Normally it’s not so quick…but it does give me pause when I see a dog-eared page halfway through a book. Should I quit? Thoughts, from you library-using readers?
Plus if you forget to unfold your dog ear it will bother the next person who takes the book out, but if you forget and leave the bookmark in, you might intrigue the next reader. Shopping lists, boarding passes… I once found a temporary birth certificate being used as a bookmark (I pictured the mom in the hospital after giving birth just wanting to finish the book… And yes, I mailed it back to her…)