Here's a quick primer on user data in ad bidding. OpenRTB 2.x user object: https://developers.google.com/ad-exchange/rtb/openrtb-guide#user-object https://deve

Here's a quick primer on user data in ad bidding. OpenRTB 2.x user object: https://developers.google.com/ad-exchange/rtb/openrtb-guide#user-object https://developers.google.com/ad-exchange/rtb/openrtb-guide#.... OpenRTB is used by publishers (Web sites) to put ad impressions up for realtime bidding (RTB) on exchanges like Rubicon and AppNexus. Ad-tech companies representing advertisers - often the largest advertisers - then place bids. Depending on how one counts, 40-50% of online display advertising occurs via RTB[1]. When people talk about how their personal data flows from publishers to advertisers, for this ~half of ad placements, RTB is the method and OpenRTB (particularly the user and geo objects) is often the protocol. OpenRTB 3.0 signed bid requests from publishers: https://github.com/InteractiveAdvertisingBureau/openrtb/blob/master/ads.cert%201.0%20BETA.md#supported https://github.com/InteractiveAdvertisingBureau/openrtb/blob.... This is conceptually similar to DKIM for email sources, and is expected to transport whether GDPR applies and consent has been obtained. OpenRTB 3.0 full draft spec: https://github.com/InteractiveAdvertisingBureau/openrtb/blob/master/OpenRTB%203.0%20BETA.md https://github.com/InteractiveAdvertisingBureau/openrtb/blob... [1]: https://www.adweek.com/tv-video/programmatic-digital-display-ads-now-account-for-nearly-80-of-us-display-spending/ https://www.adweek.com/tv-video/programmatic-digital-display...