GA4 + Consent Mode v2: measure legally, measure right
Marketing without measurement is guesswork with a price tag. GA4 is free and more than enough for a small business — if it's set up with the right conversions, disciplined UTMs and a consent banner that holds up in the EU.
1. Events and conversions — the difference that matters most
Everything GA4 records is an event: page view, click, scroll, form submitted. A conversion (key event) is one of the few events that are actually worth money: lead form submitted, call click, purchase. Pick 2–3 and leave the rest. If you measure everything as "important", you measure nothing.
2. UTM discipline: know where every lead came from
UTM parameters are small labels on your links, e.g. ?utm_source=linkedin&utm_campaign=august&utm_content=video-a. The rule is simple: every link in every channel gets its own label — including the one in your email signature. Then you can see afterwards that video A brought leads and video B brought nothing. Without UTMs, everything is just called "direct", and you learn nothing.
3. Consent Mode v2 — what the banner does to your numbers
In the EU, GA4, the Meta pixel and Google Ads tags may only set cookies once the visitor says yes. Consent Mode v2 is Google's standard for respecting that: if people say no, only anonymized signals are sent, and Google models an estimate from them. The result: your numbers are a little lower than reality — that's normal and legal. The alternative, tracking without consent, is neither.
4. The report you should actually look at
- Conversions by source/medium — which channel delivers, which one eats budget.
- Cost per conversion — put the ad spend next to it.
- Funnel: visit → lead → purchase. The biggest drop is next week's work.
One page, five numbers, every week. Not 40 reports nobody opens.
5. The checklist before you switch on ads
- GA4 property created and tag on every page
- 2–3 key events defined and tested
- Cookie banner with Consent Mode v2 active
- UTM map made for every planned link
- Google Ads / Meta linked to the GA4 conversions