Originally Posted by JDiver
You have the correct information.
chaneytexas is right on the button with his/her advice. Your PNR is recycled to another itinerary (think about it - only six letters, only 16 in the alphabet,)
I know it is a little different US vs. our Canadian English but I think we all have the same 26 letters to choose from.
From which there are roughly 309 Million 6 letter combinations. Since the maximum life of a ticket is 330 days they would need to sell more than 309 million tickets in 11 months to risk recycling PNR's.
How many passengers they have, I don't know but say at $200 each that is $68 Billion in annual revenue or more than triple their 2006 estimate.