I like telling the story several years ago where I just missed the 12:30am YYZ-YOW meaning an overnight and flight home in the morning. I arrived at the gate watching the plane push back and several other people there who also missed the flight that the GA was trying to deal with, including a rather jerkish DYKWIA SE. The GA has called a concierge who showed up moments after I got to the gate, and the concierge told the DYKWIA guy to come with her landside, and saw me there with my SE tags and told me to come along too. He spent the walk landside complaining while I said nothing, and then when we got to the concierge office DYKWIA rushes in and sits at the desk like "I'm being served first" - whatever, I stood by the door to wait my turn. The concierge goes in the back for a minute and when she comes back out before she deals with him she quietly comes over to me and gives me a hotel voucher for the T3 Sheraton and a seat in J on the first flight out in the morning. I headed to my hotel and she returned to deal with the jerk, who I doubt got the speed of service and the op-up to J that she gave me.

The concierges can do lots for you, but a lot of it is at their discretion. Being polite can go a long way.