In the good old days on CP you were given a free domestic pass for volunteering your seat within Canada and a international pass on overseas flights.
I lived in Whitehorse at the time and there was always a rush to get to the airport early to "volunteer" in case it was needed as the cost of flights to anywhere in Canada from Whitehorse was expensive and a free pass was a fantastic deal.
I was bumped in Hawaii once and received an international pass which I used for Whitehorse - Amsterdam over Xmas one year.
Ah yes, the good old days