BAT activity for user rewards etc happens off-chain at the moment, but I think the plan is to move it all on-chain when Ethereum can support that level of activ

BAT activity for user rewards etc happens off-chain at the moment, but I think the plan is to move it all on-chain when Ethereum can support that level of activity. A user model is built on-device to allow for opt-in targeted ads, but that model does not leak across the wire. Because the user model is not bound by a security sandbox, it can build a much richer model of user behaviour than even the most invasive ad-tech solutions that exist right now. So Brave claims end-users get more relevant, targeted ads and more privacy, because this model can't be accessed off-device. It sounds good in theory, and now ads are live we'll get to see how true it is in practice.