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.