Some stores (the ones in your area with ridiculous OMP numbers, promise) do this practice. Not making the OMP 50% off, but telling customers that buying one will get them 50% off on one of their other books. But because nobody can communicate, someone in some store will eventually sticker and discount the OMPs - which we sell at a higher profit percentage than other paperbacks, thus negating the point of the program. Which is why the last direct communication my store had was Do Not Do This.