As a gate agent at a major hub, I work many flights in a day. Part of my job is to clear the stand-by list for my fellow staff travelers. Gate agents try to give you a good seat whenever possible. So please, when you are not going to make a flight that you have placed yourself on a list, cancel it! We save those seats until 15 to 30 minutes before departure. We could have used it for someone else.
And REMEMBER.....never leave the boarding area until that plane is GONE!
Enjoy the Journey!