Stacking The Shelves is all about sharing the books you are adding to your shelves, may it be physical or virtual. This means you can include books you buy in physical store or online, books you borrow from friends or the library, review books, gifts and of course ebooks. It is hosted by Tynga's Reviews.
I got one book from Amazon (left) and the stack is from Bookoutlet.
I'am too lazy to put links.