Longer answer: we would be selling anonymous ad spaces based on matching tags (like standardized keywords) on-device/in-browser against a set of tags for ad deals whose buyers sign up to pay us only when those ads perform (have anonymously confirmed viewable impressions).
The tag matching is private -- no cookie or other identifier comes out of the device/browser, no tags out either.
The (few, three or four) tags for each ad space come from local inference, weak AI, running on-device. The goal of this AI is to work for you on your device, studying your data, to pick the best small set of tags for the ad space. Only a few, even just one, spaces per page might be filled. The ad serving is async as well as sandboxed, so it doesn't delay page load.
This private and device-local inference uses the sum of your browser state, which is a superset of what remote trackers see via cookies and fingerprinting. Think of tab opener relationships, absolute viewability/visibility, evolution from search and social interactions to browsing sites to buying. As with browser history, you can clear the summaries inferred from your data.
We are building cross-device, client-private-key-encrypted sync (as other browsers offer, although not always client-encrypted). To handle inevitable key loss, as with user multisig wallets, we will rely on a separate Key Recovery Service. So we won't have keys for your data or the results of inferences made from it. But you will have the benefit of inference studying all your browsing on all your devices, as they sync and the inference runs incrementally.
If we pull all of this off, we'll have built a private data platform where our users own their own data cross-device, along with valuable results from analyzing their data on their devices. Kind of an upside-down, individuated, private Google.
You're seeing movement toward "segment of one" marketing tech (companies who track you as an individual, across apps and even offline credit card purchases). These trackers may run afoul of regulators, as they zero in on PII.
We think Brave's way of defending your data on device is better: more precise and of course more private. Clustering among users and sync'ing with non-browser data can come later, and via ZKP protocols like the one we're using for the Brave Ledger (see https://brave.com/blogpost_3.html).
We also see IoT (home, car, internal/wearable computing) as a field in need of our "anti-cloud" approach. Of course backup is important, and some transacting with cloud services wins, but giving all your data away from the start puts you at a permanent disadvantage. It also accrues rising privacy and security risks.
Users won't get paid fairly for their attention and time (never mind their location and health data!) until they defend all such data from trackers. We're building a system for doing this, using a browser as first line of defense. (There will be other lines of defense.) Anonymous ads are just one way to get users their fair share.
Our principle of users getting their fair share means we take the same ad revenue cut as our users get, and pass the bulk on to the publisher or website (or account, if YouTube or the like). We'll follow this principle for other possible revenue including from search, if we can work that out.
Your data, on your devices, with a fair share to you, are key points of the brand value we hope to build.
