I know a lot depends on what time of day you fly out as well. Those 6am flights, many people don't take them. I do because usually the loads are always lighter. Many people I guess just don't want to get up so early in the morning.
6AM IS too early! The security lines are unpredictable so if I had a 6AM, I would need to get to the airport by at least 4:45AM. Its at least a 30 minute process to get to the airport, park my car, take the shuttle bus to the terminals (4:15); getting ready in the morning is another 45 minutes (3:30)... so If I have to get up at 3:30AM to make it to a 6AM flight, I'd rather fly the night before and spend the night in a hotel! Sorry if this sounds like complaining. I just think 6AM flights are impossible! Just my two sense.
