Let me see...
Maybe give MP members a "Bumping Compensation" profile section where they can specify:
1 - if they will participate
2 - the expectations for different situations (i.e. how much for how many hours)
Then make them agree to some T&C that totally gives UA power
Then pop up offers on the United App when flights are oversold and start pulling people based on the cost to UA.
I am sure IBM Watson would be glad to do this