This is more flimsy than I thought it would be.  The back of it is cardboard.... or something very similar so you can't have it standing anywhere other than against a wall.  The books would push it out if they were heavy enough.  It is a bit unstable too.  And I didn't realize that each shelf could only hold 20 pounds... which isn't much if you have a lot of books.  But, I'm grateful to have it!