A popular business model for the web is to get attribution and payment for conversions, for instance purchases or sign-ups, which result from the click on an ad. Traditionally, such attribution has been facilitated by user identifying cookies sent in third-party HTTP requests to the click source. However, the same technology can be and has been used for privacy invasive cross-site tracking of users.

The technology described in this draft specification is intended to allow for ad click attribution while disallowing arbitrary cross-site tracking.

• Support ad click attribution.

• Preserve user privacy, specifically prevent cross-site tracking of users.

Repository: https://github.com/WICG/ad-click-attribution

Link to spec: https://wicg.github.io/ad-click-attribution/index.html

Blog post with more background info: https://webkit.org/blog/8943/privacy-preserving-ad-click-attribution-for-the-web/