Marcin Miłowski

☠️ 💀📢 Google has changed the GA4 cookie format without any prior notice or warning. If your tracking setup relies on directly accessing GA cookies, client IDs, or session IDs, you should immediately audit those implementations. This change may silently break data collection, attribution, or integrations that depend on specific cookie formats.👇 Who is likely affected: >> Multiple users have reported that their Measurement Protocol (MP) setups have stopped working. Check your MP setup. >> Many server-side GTM setups extract the session or client ID from GA cookies to enrich data. If they are not using GA4’s get APIs or are parsing cookies directly, they are at risk. >> APIs or middleware designed to forward client data to GA4, BigQuery, or other analytics platforms may break if they rely on cookie-parsed IDs. >> Some attribution engines (especially marketing automation or multi-touch attribution tools) rely on _ga cookie formats for user stitching. They may now fail to associate sessions correctly. >> Tools that use GA’s client ID or session ID to match a web session to a lead may now collect invalid or missing IDs. >> Some 3rd-party platforms (like segment. com, RudderStack, or custom CDPs) may have integrations that assume a fixed GA cookie format. As a long-term fix, avoid relying on GA cookie internals as it prevents breakage from undocumented changes.

💥 The real definition of organic search marketing channel (or organic search traffic) in #GA4 is not mentioned even in the official documentation by Google. 🚨 In GA4, the labelling of Organic search marketing channels (or organic search traffic) is based on two main factors: 1) The source matches a predefined list of search engines and/or 2) The medium exactly matches "organic". . . When a traffic source matches a predefined list of search engines, it does not matter what their traffic medium is. For example, traffic from 'dogpile .com / referral' is labelled as organic search traffic because 'dogpile' is one of the search engines recognized by Google. Similarly, Traffic from 'lite .duckduckgo .com / referral' is labelled as organic search traffic because 'duckduckgo' is a search engine that Google recognises. Once the primary domain is recognized as a search engine, any subdomain it has become irrelevant. For example, Google considers traffic from 'test .baidu .com' or traffic from 'translate .yandex .com' organic search traffic because 'Baidu Google consider traffic from 'test .baidu .com' or traffic from 'translate .yandex .com' as organic search traffic because 'baidu' and 'yandex' are the search engines recognized by Google. . . Likewise, when a traffic medium exactly matches 'organic', it does not matter what its traffic source is. For example, traffic from '(not set) / organic' is labelled as organic search traffic because the medium is 'organic'. . . Any traffic from Google-owned property which is not explicitly tagged as paid is treated as organic search traffic. So traffic from 'google/(not set)' will be labelled as organic search traffic. Traffic from 'google / email' will be labelled as organic search traffic. Similarly, Traffic from Google lens 'lens .google .com / referral' will be labelled as organic search traffic.

📢 Updates to attribution models in #GA4 🚀