Interestingly, sometimes the flight crews don't even know they're working a ps flight. This was the case on a two-class 777 flying EWR->LAX on July 29. I was chatting with very nice FSC/purser, and I said something about how the ps flights are really nice, and she said, "PS? What's that?" I explained, and she was interested to hear about it. This was an international pmCO flight crew, so not so surprising they weren't aware of ps.