WiseFlyer

<Usual disclaimer about not being sure if this is the right place to post this/hope the Mods will move it as needed>

I'm just back from a trip that involved award travel on three airlines, and only one leg used miles from one carrier (AA) for travel on that carrier. The others used AA or BA miles for travel on various partners. I realized I don't have a clue how the airlines compensate each other for award seats and I assume it may be interesting to others as well. If I use AA miles to fly CDG-LAX on Air Tahiti Nui, or BA miles to fly AMM-ORD on Royal Jordanian, what do AA or BA give to Tahiti or RJ in return for the seat?

We read a lot of speculation about what non-airline partners (banks, especially) pay airlines for the miles they give out as bonuses, but I haven't seen anything about what an airline gets for giving up seats to partners' accountholders.

If this has been discussed elsewhere, I'd love a link to the thread. And if it hasn't -- can a guru enlighten me?

Thanks in advance!