Certainly. The principle challenge we had was this notion that the registry had to be updated in real time, simply due to the fact that we have a very wide array of advertising systems. People who run campaigns with Google will do search ads, so they show up on your search results. They can be YouTube ads—video—or TrueView. You can skip it, and also display advertising that shows up on third party publisher sites.
In the case of the third party publisher sites, those ads are often being served by third party ad servers. We don't necessarily have immediate access to the creative ourselves. For us to update even our own registry in real time, let alone the registry of a third party that had to maintain their own registry, would be very challenging.