Privacy Preserving Ad Click Attribution for the Web

The only data needed for measurement is that someone who clicked an ad on Site A made a purchase on Site B.

Today we are presenting a new technology to allow attribution of ad clicks on the web while preserving user privacy. Here are the important privacy aspects of this step:

To achieve ad click attribution, the browser needs to be able to match conversions with stored ad clicks. A cross-site anchor element that wants to push ad click attribution data into the browser looks like this:

To debug such elements, you use the Web Inspector’s console with the “Preserve Log” setting enabled.

Source: webkit.org