Why does every system tell a different story?

I’ve sat in meetings where GA4, BigQuery, and the CRM all disagreed — and each side had numbers to prove they were right.

Awkward silence usually follows.

Where identity falls apart?

Each system plays by its own rules:

• GA4 stitches and aggregates
• BigQuery stores raw events
• CRM records deals by its own keys

Without shared identifiers, you’re not tracking users — you’re tracking fragments.

What’s misunderstood here?

This isn’t a “data mismatch” problem. It’s an identity governance problem. Until IDs are aligned, comparisons are meaningless.

How I usually fix it

I define a master ID and build explicit mapping rules across client_id, user_id, and CRM identifiers. Then I run reconciliation: 1→1 matches, 1→many splits, and missing links — before touching attribution.

Have any idea? Welcome to the comment section!

Want all my best GA4-BQ queries in one place? I turned them into a Chrome extension — top SQL queries you can search and copy in seconds.

Go here to install it for FREE.

Prefer the web version? It's here.