But then, didn't the multipool pay out through using the FeeShare sale money? If so, what coins are actually generating the interest for FeeShares?
Urg my head hurts.
Yes and yes. The multipool distributes from Exchange help SHARE, then places a BUY order at that price to replace that SHARE back into the Exchanges wallet.
So, the net change of SHARE that the Exchanges holds due to the multi-pool is 0.