Price/quality issue.  I called Wayfair to provide the necessary feedback.  I ordered from wayfair these shelves because I had higher expectations than a cardboard back to a furniture even if just a bookshelf.  I have this perception that wayfair is a higher end provider for furniture than another supplier. To my disappointment, I also had to glue the bottom piece.  Customer service was very cordial and took our feedback very positively.  I would recommend wayfair to reevaluate this item - price vs. quality  etc.