That's not always possible on every flight. Every airline has a different system and set of rules. Some airlines don't offer a system for paying for emergency e

That's not always possible on every flight. Every airline has a different system and set of rules. Some airlines don't offer a system for paying for emergency exit seats. Other times the seats might already be booked. Sometimes the cost is prohibitively expensive. When that happens you're stuck with the situation of having your knees caps smashed, just so someone can tilt their seat back a few degrees. It's a very strange situation to agree that someone should have a small privilege to the discomfort or even pain of someone else.