Stores may be willing to tell you exactly how many items they have in inventory, but airlines will never do this. That information is just too valuable to competitors.
This may seem obvious, but there was a time when it was new information to each of us.
Not true. Southwest apparently is one of the few that doesnt...Thus why I asked.
Here is one of the several sites out there that will show you seat availability by airline.
http://www.seatcounter.com/?