I'm a non-Googler who has spent a lot of time around media analytics, and I'll make the same insistence that that is a true and important statement. Google is

I'm a non-Googler who has spent a lot of time around media analytics, and I'll make the same insistence that that is a true and important statement. Google is a one way mirror. They will suck in as much data as you want to give them about people, but it's virtually impossible to pry any info out of Google that's at an individual and identifiable level. Only aggregated performance information is exposed to advertisers, and the ability to mix and match targeting criteria based off of those dimensions that they expose. Even with their enterprise marketing products like DoubleClick you can't pry out individual-level data. DoubleClick customers used to be able to export an anonymous ID, so they could use independent third-parties to consolidate conversion and impression data and measure attribution across complex marketing campaigns. But even that isn't possible anymore, due to GDPR concerns[1]. The closest they now get to "sharing" user data is Ads Data Hub[2]. And by sharing, I mean they expect you to share all of your data from outside of Google, which Google will then connect to their data and allow you the privilege of running aggregated queries. But they actually keep their side of the data firewalled off, and it's not human readable or accessible at the row level, only in rollup queries. In the ad world, I can assure you they are far more protective of user data than most anyone else. The size, effectiveness, and dominance of their marketing channels afford them the ability to take that position without it materially impacting advertiser spending. Very few advertisers take such active measures to insulate exposure of user data from advertisers. And for many that do invest resources in such endeavors, it doesn't mean that they don't provide user data to advertisers. It just means that they don't provide it for free anymore. [1] https://adage.com/article/digital/google-s-move-remove-doubleclick-id-presents-issues/313415/ https://adage.com/article/digital/google-s-move-remove-doubl... [2] https://developers.google.com/ads-data-hub/ https://developers.google.com/ads-data-hub/