Was traveling MCI - ORD last week. My original flight was overbooked, GA requested volunteers. I was 1st on the list, 3 volunteers were needed and I was selected and re-booked for the next flight, about 2 hours later.

For the following flight, the GA again announces a request for volunteers. Again, I'm 1st in line. After boarding begins, the GA announces that no volunteers are needed and that all should board, which I do accordingly.

However, after all passengers have boarded, the GA comes onto the plane and informs a person seated in front of me - we're both seated in Y (who I saw volunteer after I did) that they would like her volunteered seat.

So, how is the VDB list processed? I'm guessing not according to order in which the passenger volunteered. I'm 1P, so I figured that this other passenger must have been 1K, UGS, etc. Does fare class come into play?

I may be wrong, but I don't think there is a set process (like standby).

The GA usually prefer someone that has the easiest reroute. This also results in the least amount of compensation. They also prefer those without checked luggage, though I think this is a minor consideration.

Maybe they were able to put someone on a direct flight to their destination (and arriving about the same time), or they were ending in next stop without checked luggage.

The VDB list is arranged in the same way as the standby list. The Departure Management list handles all of it and it sorts each category the same way. This doesn't mean, however, that the GA will process the passengers accordingly. It can be much easier and less costly to accept a non stop passenger as VDB than a connecting one.

Recently I was first on the VDB list out of 4 passengers. They needed 2 seats. Two of the four were a couple, but since I was first they asked me and the other single passenger if we really wanted it. The other passenger really didn't want it but deferred to me (he must not have been an FTer). I said I definitely wanted it. The GA told the couple to board with their original seats. It turned out they did have one more seat so the remaining guy got on board. In this case it seemed that my position on the list was what counted since the GA kept referring to it. However, if it were just me and the couple, they would have received the VDB. Sometimes it depends on what they need versus who is volunteering.

According to CSRs I've talked to, it follows the same order as the DM list: status, then fare basis, then time on the list. However, the goal of the GA is primnarily to get the plane out on time, and secondarily to get you where you are going. If a different order makes that easier to do, that's what they are likely to do.