I had no idea it could be so difficult to find a very narrow bookshelf.  I had an odd space that needed shelves and this was the only one I could find.  It is sturdier than you would think.  I have all five shelves loaded down with as many books as it will hold, and it's handling it just fine.  I've had this shelf for a couple of months and I can't see any sagging or leaning of the unit.  As other reviewers have stated, it seems to get sturdier the more weight you add.  Also, it took less than 5 minutes to put it in place.  There is no assembly-it took longer to get it out of the box than to get it set up in the room.  Very happy with this purchase, the price and how quickly it arrived.