Originally Posted by
Gspeed
The extras shown are the ones sold to HKs (who have not yet checked in for the flight). Delta (and most airlines) block a certain number of customers from getting seat assignment until check-in or at the gate. I don't know why the two sources of numbers use different data...
Exactly. It's just two different pieces of information that can be considered separately. The first screen shows how many seats in a cabin are booked/how many more of them they will sell.
The airport standby list shows seats unassigned. Theoretically (although it wouldn't happen in reality) you could have screen 1 showing all seats booked (0/0) and the airport standby list showing every seat unassigned. In that case, both pages would still be telling you the truth.