I have a book with the decoder. Mine is also 1/2 empty! How do the US stickers differ from the Argentina ones? To me the contents of the packs look the same and the stickers inside match the book! The only thing I see different between the US and Argentina stickers is that the bags are advertised on the back and the US ones also have the corresponding place number. The Argentina stickers do NOT say which sticker they are, but the pictures on both the Argentina & US ones are the same!