Cookieless

Cookieless is a state of digital marketing in which third-party cookies (which used to allow tracking of users across sites and building advertising audiences) no longer work or work to a limited extent. Safari and Firefox blocked third-party cookies back in 2020–2021, iOS 14.5 (2021) introduced an ATT request, Google Chrome - the last major browser - has been implementing a phase-out since 2024, although the time frame has been shifted several times.

What's really changed by 2026: Based on client project data, I estimate that 40-60% of mobile conversions are not attributable to standard pixel methods. This means that Facebook Ads Manager, VK Ads and Google Ads show ROAS, which is actually higher than the actual one (some conversions are simply not visible to the system). Advertisers who don't know this are making poor budget decisions.

Three practical answers to cookieless that I use in my work: Server-Side Tracking (CAPI / Conversions API - transferring conversion events directly from the server, bypassing browser restrictions), First-party Data infrastructure (own CRM audiences instead of pixels), and MMM for evaluating channels where attribution is impossible in principle.

Some platforms have offered their own solutions: Google Privacy Sandbox with Topics API (audiences based on topics of interest without identifying specific users), Yandex Crypta (its own matching system based on authorized users of Yandex services). For advertisers with a large share of Yandex traffic, this partially solves the problem, but does not solve it completely.