Honestly, I don't know why you need a blockchain in the first place. Just run your own accounting servers, which you already are doing for the Anonize ballots. It is certainly possible to take in money from identified (i.e. non-anonymous) users and pay out money to identified publishers without being able to determine which users are responsible for which payments to the publishers. However, I also don't see any problem with using Ethereum for transferring money.
Oh, that q ("why you need a blockchain") is easy. Fiat only would require us to be an MSB or MTA, heavy licensing lift and no ability to grant users for free from the user growth pool we precreated before the BAT sale. The user growth pool is the number one reason in my view.
Also we like macro-auditability from funding wallet to omnibus settlement, to show we took the %ages we promised.
