Chrome has proposed a number of technologies within the Privacy Sandbox that would allow marketers, and partners working on their behalf, to measure campaign performance without third-party cookies. These proposals protect consumer privacy while supporting key advertiser requirements, such as event-level reporting that enables bidding models to recognize patterns in the data, and aggregate-level reporting which delivers accurate measurement over groups of users.
By using privacy-preserving techniques like aggregating information, adding noise, and limiting the amount of data that gets sent from the device, the proposed APIs report conversions in a way that protects user privacy. For example, an event-level iteration of the API is currently available in origin trials for measuring click-through conversions. It protects privacy by introducing noise and limiting the bits of conversion data that the API can send at a time. As a result, advertisers will have to prioritize which conversions are most important for their reporting needs.
Over the coming months, Google’s ads teams will continue evaluating how the proposed conversion measurement APIs can be used alongside Google’s measurement products to support use cases such as reporting view-through conversions, determining incrementality and reach as well as performing attribution. We recommend customers implement sitewide tagging with the global site tag or Google Tag Manager in order to minimize disruptions during this time. More decisions will have to be made before a prototype is built — including what the right level of noise should be and what’s the minimum number of conversions to include when sending an aggregate-level report — so we invite ad tech companies, publishers and advertisers to get involved in these discussions within the public forums.