The Payload Optimization program has been in effect at Delta for several years (2007). It essentially looks at current and historical load information and compares them with actual limitation weights for the given aircraft for the conditions on that day. There are a number of weight limits on an aircraft that have to be considered in performance planning: Things like 'Placard' weights including max taxi weight, max takeoff weight, and max landing weight (this is the one that generally gets short domestic flights where weather requires alternate fuel to be carried). There are also performance based weights like the Runway Allowable weight and Climb Limit Weight (these are the ones that often get Interantional flights particulalrly on hot days with high altitude airports or short runways).

In any event, if the Payload Optimization program sees that todays load is within a certain window near a limit weight, a number of different departments are notified that that flight is being payload optimized. As the Captain, I get a big note on my flight plan. The Gate Agent is alerted via a message on their screen. In general, this program should be transparent to revenue paying Pax and there's really no need to discuss what happens behind the scenes. However, one restriction on the GAs is that they can't load any non-revs without specific authorization. I would not normally expect a Gate Agent to use the phrase in a PA announcement (though I don't know of any restriction against doing so), but it does let any nonrevs in the gate area know the reason that they aren't being cleared at that time even if the screens show open seats. The problem is that outside of Pilots and Gate agents, many nonrevs (particularly buddy passes, parents, and dependents, and employees form other departments) would have no idea what Payload Optimized means. In the end, the 'non-rev' portion of the program attempts to avoid loading a nonrev on a weight critical flight only to have the Agent come on the plane to pull the nonrev and make them perform the 'Walk of Shame'.