I'm sure there has to be a flight at sometime with economy seats. They have move me fare classes too as in up and I got the extra points to go with it. I have gotten on many flights that were "sold out." One can always stand by. I've been flying CO 13 years and they always got me to where I need to be. I have even messed up booking before and didn't realize it ( has to do with time zones)until I'm about to do my flights and CO fixed it for me no charge. That they can say sorry your out of luck cause you screwed up, but they fixed it and no charge.