Ad Tech Strategy: Targeting and Measuring Ads Once Third-Party Cookies Are Gone

You are a product manager working on advertising at Rakuten. Third-party cookies, which the ad industry has long used to recognize the same browser across different websites, are being blocked or restricted. How would you keep advertising effective without them? Explain what stops working, how audience targeting and results measurement should change, and what you would build first. ```hint List what the cookie was doing Before proposing replacements, separate the jobs third-party cookies performed across sites, such as finding audiences, capping frequency and linking an ad to a later purchase. Each job needs its own replacement, and some replacements depend on data a company already holds. ``` ### Clarifying Questions - Whose needs come first: advertisers buying campaigns, publishers and networks selling ad space, or the platform that connects them? - Is the scope only the web, or also mobile apps and connected TV, which rely on device identifiers rather than cookies? - Which regions' privacy laws and consent rules must the plan satisfy? - What first-party data, such as signed-in accounts or purchase history, may the advertising business use, and under what consent? ### What a Strong Answer Covers - A clear account of which advertising functions break without third-party cookies: cross-site targeting, retargeting, frequency capping and conversion measurement. - Replacement approaches for targeting, such as consented first-party data, contextual targeting and aggregated audiences, with their trade-offs in reach and precision. - A measurement plan that no longer depends on cross-site tracking, such as server-side conversion data, clean rooms, incrementality experiments and media mix modeling. - A prioritized plan covering advertisers as well as publishers and networks, with metrics that show whether campaign performance and revenue held up. - Privacy, consent and regulatory risks, including why fingerprinting is not an acceptable substitute. ### Follow-up Questions - An advertiser's retargeting results fall sharply once cookies disappear. What would you offer instead, and how would you set expectations? - How would you cap frequency for a campaign running across many publishers without a shared identifier? - A partner proposes matching users across sites with hashed email addresses. What would you need to see before agreeing?