Three for two vs one and a half

Scott Pack writes a post here: Me And My Big Mouth: Blog One Get One Half Price about the economics of "three for two" (currently Borders on selected books and WHS on all books) and "buy one get one half price" offers (Waterstones, previously the "owner" of the 3 for 2 promotion, according to Mr Pack, who was their chief buyer, once) on all children’s books). Whichever way you look at it, it doesn’t seem to work for the publishers. Where will it all end? On the Internet?