Unremovable bar code sticker glue - Why did you change to this method?

Although I am always happy with the quality of my blurb books I must say how disappointed I was with my latest 2 book order.  Instead of having the barcode printed on the back of the book, you plastered on large barcode stickers to the back.  There is no way to remove the sticker without leaving all the glue remaining.  I’ve tried to rub off the glue (soft cover book) but the glue just smears all over the back which completely ruins the books as far as I am concerned.  Now I have two books that will stick to anything including each other.