Still, Jordan told the Times that by charging bag fees, Southwest predicts the number of checked bags will decrease while the number of gate-checked bags will "modestly" increase. And when there are gate-checked bags, Southwest agents have a ballpark idea of how many to expect when they use a tool on their devices to help predict that number.

Bob Jordan recently introduced major changes to the way the low-cost airline works, which caused a stir among loyal fliers and left them wondering what sets it apart from competitors.

Specifically, the airline expects to make $4 billion from both the new bag fee rules and the end of its open seating policy. The bag fee change alone is going to account for a huge portion of this amount,