US airlines collected $3.4 billion in bag fees in ’10, up 24% from ’09 according to a DOT report. Absent fees, airlines would probably be losing money. Las Vegas based Allegiant generated 29.2% of all their revenue from extra fees, more than any airline in the world. Among US carriers Delta generated the most revenue from bag fees; $952 million. United/Continental was next at $655 million, American $580 and US Airways $513.