According to an article in the Wall Street Journal: Airlines have increased restrictions on cheap fares by raising overnight requirements, upping what had commonly been only a onenight stay requirement to two and three nights. The overnights can be weeknights, so those tickets aren't as onerous as Saturday night stay tickets. But the three-night requirement does limit the utility of discounted fares for road warriors. What is a "road warrior"? Why would a company put restrictions on a service that make the service less desirable to some of its customers?