Unless the fares were mistakes (which most carriers correct before you fly) you have been profitable. I don't think airlines sell loss leaders. A friend once told me that the difference in cost between an empty seat and a passenger in that seat for a MSP > AMS TATL was about $72 so anything over $72 was profitable. This is effectively the incremental per passenger cost once they've sold enough fare to cover the base cost of operating the flight (eg, flight specific personnel, fuel, maintenance, depreciation, port fees) + flights share of corporate overhead.

They'd rather have your $73 than nothing at all. But they'd really rather have your $800 so they have to be careful what they offer or everyone will wait for the super cheap last minute fares.

Most business travel is relatively elastic pricewise - they have to go and will pay what it costs. About 80% of my travel though is fairly optional. With $800 fares to Europe I'll go 4 - 6 times a year, at $1200 I'll only go once. The game for them is figuring out if they benefiting enough from people who'll pay the higher fares to offset the loss of business from people like me.