What?
Store the actual bookings generated by the ORS/DS so they can be consumed by players directly (per flight, fare etc.), used as input for aggregate reports or employed by downstream features (for example for dealing with no-shows/cancellations or to use them for accounting/billing purposes).
Why?
Even if not available for aggregate reports: It’s cool to see individual bookings 
But the idea would be to use them for reporting of some sort that would massively improve insights into how a network performs and why.
When?
This is highly experimental as the amount of data to be stored is enormous and making it accessible in a fast and dynamic fashion requires some engineering effort.
It would make the most sense in combination with Individual Travel Request Generation and Custom Booking Classes, but neither is really a requirement.