An article in the current issue of the airline trade publication AIR TRANSPORT WORLD talks about how sophisticated airline booking software has become. Carriers are now (or soon will be) able to analyze what flyers are spending, with an eye toward weeding out high level elites who do it on cheap fares. They also want to find the less frequent traveler who, while not racking up big miles, always buys full fares, and thus spends more than some of the super elites. The common denominator is the person's frequent flyer number. At present, if someone doesn't put their numbeer in at the time of a reservation (which sometimes happens with agency bookings) but adds it later, the information is not always picked up. In any case, yield management is watching you!!