I've helped out on flights before. People are of course appreciative.
Although, one time there were some angry passengers who were miffed that because I suggested we divert a flight (which the pilots did in very, very short order....I had no idea a mainline airplane could land so quickly) they missed their connection. I think these idiots made a point of speaking loud on their cell phone so I could hear why it was just "ridiculous" that we had to divert to get the ill passenger (who was having a stroke) off the plane.
I didn't expect anything from Delta (except a reconnect on my connecting flight of course) but they did send me a nice Thank You letter and a travel credit....I think $200.