Delta Air Lines: The U.S. king of ancillary revenueNewsBy Dennis Schaal | December 21, 2009Share This article was originally published on U.S. airlines took in some $2 billion in fees for ancillary services in the third quarter, a 36.4% increase over the same period in 2008, and Delta Air Lines clearly was the most aggressive carrier in its fee-collection activities.The details, from a report by the U.S. Bureau of Transportation Statistics, show that Delta's ancillary revenue efforts, which brought in $447.5 million, had no serious competition. American Airlines came in second at $261.2 million for the quarter.Plus, when you take into account that merged airlines Delta and Northwest Airlines reported their numbers separately, then their combined $670.8 million in ancillary-fee revenue stands out as even more impressive -- or notorious, depending on your perspective.At times lost in the discussion about ancillary revenue is the fact that the category takes in much more than bag fees. In fact, the above numbers also include change fees and charges for pet transportation, standby and sale of frequent flyer miles to the carriers' business partners.Delta also topped the other airlines in the ancillary fees it took in per passenger at $24, but the airline was far less dependent than other major U.S. airlines in getting that revenue from bag fees, according to the DOT numbers. So Delta collected $7, or 29.2%, of that $24 from bag fees. [About $6 of the $24 in fees that Delta collected per passenger came from change fees.]In contrast, airlines such as United Airlines, Continental Airlines and AirTran Airways took in roughly half of their ancillary revenue from bag fees.Clearly, ancillary revenue is a category in the process of undergoing a radical transformation, one with far-reaching implications for travel technology, distribution and customer service.Two years from now the pecking order among airline fee-collectors may be substantially different.And, certainly the types of fees collected will be much broader.