Making a list of books you have/are selling is a bit of dubious pleasure. Looking at the books you have makes you evaluate your own reading habit and your taste in literature. What if the books you list are, coughlowbrowcough, or at-least appear so to others. Or other way round? What if others evaluate your bookshelf based on what you are selling. Perhaps the ones you’re selling are the ones you enjoyed purely for fun and therefore disposable. Perhaps they are the ones you attempted but gave up for various reasons. Or perhaps these were un-loved, un-needed books thrust un-asked on you by others.
Why does one ascribe greater relevance and import to books, a greater signifying power than are theirs intrinsically. The value of information about/on the book is indeed greater than the value of the book itself.