I find the gate or airport agents not really helpful to standby passenger with discount tickets. They often tell me to wait until very last minute even when the plane is half-empty. For some reasons they refused to tell me my chance of getting on and they just print me a gate-pass to go for waiting.

I don't quite understand their logic. If the plane is half-empty half an hour prior to departure. Do they expect to get them filled within a few minutes? Why can't they simply give me a boarding pass at check-in? The person who drops me at the airport has to wait for me to get an answer. If there is no seat, then I will go back to the city to wait for later... These agents really need to learn how to make the passengers and their faimly's life easier.

On the other hand, I will give them some credits on their worry. If a flight is cancelled or missed, those passengers have highest priority (even above SEs) for the next flight out. So keep this in mind when you stand by for a later flight, if the one before it is cancelled, then an empty flight becomes oversold all of a sudden. So don't stand by for the last flight of the day to go to important places if I were you.