Also the seat available is not really accurate either. Click on the little icon on the right, it lists all the nonrevs, then click the active standby list. It lists all the standby folks who have checked in but is says seats actually remaining, and it always way more than orginally posted. I really don't know why. Maybe someone here knows why...
But as far as nonreving, its really a game. Always have a backup plan too. Or just don't go.