The nightmare began for Michelle Peluso sometime early in the morning of Apr. 5, 2005, when an incorrect fare from Los Angeles to Fiji on Air Pacifica was mistakenly loaded into the reservation system used by the online travel agency. Before long, someone with the screen name "channa" posted a note on FlyerTalk, a popular message board with frequent travelers. "LAX-NAN (Nadi, Fiji) -$51 all in - Travelocity!" read the subject line.

The post was blood in the water for the Web site's sharp-eyed community of "mileage runners," who troll online travel sites for extremely cheap or misfiled fares to distant cities as a way of racking up airline miles. In no time, Channa's discovery had helped prompt more than 400 bookings among the frequent-flier cognoscenti eager to take advantage of the fare, which was displayed to travelers as $0 plus $51 in taxes. The potential cost to Travelocity.com if Peluso decided to honor the clearly erroneous fare: almost $2 million.

Get the full story at BusinessWeek