Like I said before, instead of charging a fee and returning 70% of those fees as discounts, (a large part going to the BTC wealthy,) simply charge 30% of the fee you're trying to charge in the first place.
EG: 0.003BTC or 0.15% on all withdrawals.
+1
You pay a transaction fee of X BTC to send coins out. Flexcoin includes a transaction fee of Y BTC in the transfer. X is easy to calculate from the transfer amount, because it is set by Flexcoin policy using a simple formula: X=max(0.01,amount*0.005). Y is not easy to calculate in advance, because of the way the bitcoin client works. But you don't care, because you don't pay Y directly, you pay X.
Next, Flexcoin calculates Z, which is the sum of all the cash out fees paid by users (X), minus the sum of all their paid network transaction fees paid by Flexcoin (Y). Z is their operating profit for whatever accounting period they use. They then distribute 70% of Z back to depositors as profit sharing (their lawyer makes them call it a "discount" so they don't have to file paperwork with the IRS), and they keep 30% of Z as their net profit.
Is that clearer?