Lesson 1 of 5
Why Migrate At All
Most sites you inherit already have tracking, just not in GTM. A GA snippet in the <head>, a Meta Pixel pasted into the footer, a Google Ads tag a developer dropped on the thank-you page two years ago. Nobody is quite sure what's live or who owns it.
What GTM gives you instead
- One place to see and change every tag, without a developer deploy.
- Versioning and rollback, so a mistake is one click to undo.
- Consent handling applied consistently across all tags.
- An auditable record of what fires, when, and why.
Migration is the unglamorous but high-value work that turns chaos into a system. Done carelessly it double-counts or drops data; done well it's invisible to the numbers and a relief forever after.
Key takeaway
Migrating consolidates scattered, hard-coded tags into one versioned, consent-aware container you control. The goal is the same data, better managed, with no blip in the reports.