The monetary value of the ticket factors in at the second level in the fare class. After fare class is the time of booking. So me (Diamond Medallion) flying on a Y-fare would trump any Platinum member no matter how expensive their ticket. So to put this is in perspective I am the highest level of the FF program at delta flying on the most expensive fare class in coach and am not getting upgraded. I think that alot of people are not getting upgraded in the windows before the flights, so they are using Regional or Global upgrade certificates within the 24 hour window.