Last week I flew JFK-BOS to position myself for a MR. My efforts to fly standby were quite frustratingly unsuccessful. I arrived at the airport expecting to just relax a bit before my flight, not even thinking about flying out early. That was before I got the notice that my flight was going to be an hour late and likely cause me to miss my dinner in Boston. With a bit of motivation and luck that the TSA line was pretty quick I was through to the gate 20 minutes prior to the earlier flight’s scheduled departure time. Surely it would be no problem to get myself on a standby list and, with any luck, up to Boston in time for dinner. The gate agent was busy so I stepped over to the service center right next to the gate. "Sorry, but you cannot be added to the standby list. The flight is closed." Mind you they were still boarding the flight and they had a dozen or so folks standing around waiting to see who would clear off the standby list into one of the few empty seats still available, but they guy I was speaking with insisted the flight was "closed." I tried with the gate as well and couldn’t even get a word in before I was dismissed by the agent. At this point it was pretty clear I was not getting on the flight but I was also curious to see how the event would play out as there were a number of non-revenue passengers also waiting for seats and I was curious how many of them would get to fly ahead of a revenue customer. The answer was at least 5. I waited 90 minutes for a supervisor to show up and explain the policy to me and clarify my inquiries regarding the priority for the list. They never showed. Eventually I had to go catch my actual flight. VERY disappointing experience with the ground crew in JFK. Oh, and if you plan on flying standby make sure you're at the airport entirely too early or they may just decide to skip you, too.