Some people wrap their ego completely around their classification. So it apparently does a lot for them. Other people don't care at all. In USPSA the classification ranks shooters based on their ability to shoot, reload, draw and transition between targets. Classifiers are carefully measured out and set up the same all over the country. (in theory) so that we can compare all of the shooters in a given division. Grandmaster down through D class.
Details can be found at www.uspsa.org