But it can be a postcard. It's mostly saying, "We're still here! Register now and save money!" It lets folks know what hotel to make reservations for, and reminds the procrastinators among us that we'd better hurry up. (Procrastinators? In fandom? Uhhh....) I do recommend postcards or day-glo paper, though, and no envelopes!! Strange envelope = junk mail.