One example should suffice to demonstrate customer suspense. Before Continental Airlines united with United Airlines, premier Continental flyers (those who traveled fifty thousand miles or sixty segments per year) received an elaborately packaged kit containing priority baggage check tags, upgrade coupons, a frequent flyer program guide, and other incidental reference material. The first year customers received this unadvertised package, they were indeed pleasantly surprised. In year two, Continental may have managed to surprise a few customers (those who forgot the previous package). But for Continental's consistently high-traveling customers, after three, four, or five years of receiving the same old kit … well, they not only came to expect it, they considered it a ho-hum occasion. Now suppose that Continental had cleverly changed the contents each year, one year adding a humorous letter from the CEO (à la Warren Buffet's annual stockholder letters), the next, a gift gleaned from knowledge about the past year's travel (for instance, a subscription to some magazine, a free dinner at a restaurant in the frequent destination city