I recently read a debate about people who dog-ear books they are reading and how some readers (the ones who use book-marks) find this so hard to understand.
I must confess that I do both. I use book-marks but not the kind you buy. Currently I am using an old suburban rail ticket from my last train ride in Germany. At some point it will be discarded because it will simply get too tatty. I don't do this to all my bookmarks. I have a cherished bookmark from my visit to the Mauritshuis museum in The Hague around fifteen years or so ago. It reminds me of that wonderful weekend there with my daughter. She was a little dubious about going there, not being an "art freak" as she put it, but she really loved it. I just use it as a bookmark in books that I cherish - not the novels I read and then give to the charity shop. And every time I see this entrance ticket for the Mauritshuis, I remember that when we arrived in The Hague that morning there had been a power cut, the shops were without lighting and we couldn't get a hot drink anywhere. One of the many "adventures" I shared with my daughter and which will always be precious to me.
So, yes, I am a fan of bookmarks but if I'm travelling, I will usually just dog-ear the page. In fact, when I browse the secondhand bookshops, it can be very interesting to see what has been dog-eared by previous readers. Some novels are marked and abandoned, as you can tell by just one dog-ear, while others have been read all the way through (several dog-eared pages).
But, you know what? It hardly matters, does it? Either you find a book you just love to read or you put it away after a number of chapters as being not your kind of novel. That's the world of variety we enjoy.
I am currently reading John Simpson's "We Chose to Speak of War and Strife - the World of the Foreign Correspondent". It is a fascinating read and yes, I'm using that suburban rail ticket to mark where I left off reading.