Originally Posted by FoxFlyer

I'm not sure about this advice, but (#2) depends on how you obtained your ticket initially. If you purchased the ticket, then YES, you can absolutely "upfare" your ticket to a higher fare class to increase your chances. However, know that that is just one factor... depending on your status, even if you had a higher economy fare class, you still won't clear before someone with a higher status (unless you are in Premium Plus). If you know your original fare class, you can always call in or check online for what a higher fare class would cost you. But again, if everyone ahead of you is of higher status, the higher fare class won't matter (unless, of course, if you upfare to a Premium Plus seat, then you jump ahead of all other status holders in regular economy other than GS).