I used to have bookshelves, with books on them, and then I took them down to decorate. And never put them back up. I'm never going to re-read books I've already read, and books which haven't been read yet simply aren't going to be.
For some reason, it feels wrong to be giving all my books to charity shops, but they've been sitting in boxes for 2 years so I clearly don't need them.
I do think books are lovely to look at, but not so lovely that I need to put up shelves to look at them.
I do all my reading on kindle now, so my book (novel) collection will never be added to.
I have 3 shelves full of food/cookery books in the kitchen, and plenty of non-fiction on the dresser, but no fiction anywhere.
My parents' house has bookshelves EVERYWHERE. Every time I go there, I just think about the day I'll have to box them all up and take them to charity. They will never re-read any of them. Thankfully, my mum is an avid library user now, so she's not adding to it.