The short answer: before you increase ad spend, make sure your tracking is telling the truth. Ad platforms optimize towards whatever conversions you send them, so broken or duplicated tracking doesn’t just mess up your reports, it trains Google and Meta to find the wrong people. Run these ten checks first. Most take minutes, and any one of them can change how you read your results.
1. Your key events in GA4 are the ones that matter
Open GA4 and look at which events are marked as key events (formerly “conversions”). Are purchases, leads and qualified form submissions there? Are vanity events, like page views or scrolls, marked as key events and inflating your numbers?
2. One tag manager, no duplicate tags
Check that your site runs one Google Tag Manager container and that the GA4 and ad platform tags aren’t also hard-coded in the theme or added by a plugin. Duplicate tags are one of the most common causes of double-counted conversions.
3. Purchases fire once, with a unique transaction ID
Refresh your thank-you page. Does another purchase fire? Send a unique transaction ID with every purchase so repeat page loads can be recognized and de-duplicated, and make sure the order value and currency are passed correctly.
4. Google Ads auto-tagging is on, and the click ID survives
Make sure auto-tagging is enabled in Google Ads and that the gclid parameter isn’t stripped by redirects, cookie banners or your checkout. Without it, Google can’t connect clicks to conversions properly.
5. GA4 is linked to Google Ads
Link your GA4 property to Google Ads so audiences and data can flow between them, and decide deliberately whether Google Ads should optimize on its own conversion tag or on imported GA4 key events. Don’t count the same conversion from both.
6. Enhanced conversions are set up
Enhanced conversions in Google Ads use hashed first-party data (like an email address from a form or checkout) to recover conversions that cookies alone would miss. It’s one of the simplest accuracy wins available.
7. Meta’s Conversions API runs alongside the Pixel, de-duplicated
Use the Conversions API (CAPI) as well as the browser Pixel, so you’re not relying on browser cookies alone, and make sure each event shares an event_id so Meta counts browser and server events as one. Check your Event Match Quality in Events Manager while you’re there.
8. Lead gen accounts import offline conversions
If you generate leads, a form fill is only the start. Import offline conversions, such as qualified leads, booked calls or closed deals from your CRM, back into Google Ads and Meta. Then the platforms can optimize for leads that actually turn into revenue, not just leads that fill in a form.
9. Cross-domain and consent are handled
If your checkout or booking system runs on a different domain, set up cross-domain tracking so sessions aren’t broken in two. If you advertise to people in regions that require cookie consent, make sure consent mode is configured so you stay compliant without losing all your data.
10. Housekeeping: retention, internal traffic and server-side
- Set GA4 data retention to the longest option available (the default is only two months).
- Filter internal traffic so your own team’s visits don’t skew the data.
- For higher-spend accounts, consider server-side tagging, which makes tracking more resilient to browser restrictions and ad blockers.
Why this comes before scaling
Scaling multiplies whatever is already happening. If your tracking is clean, more budget means more of the right customers. If it’s double-counting or missing conversions, more budget means faster, more expensive mistakes, and reports that look fine while the bank balance doesn’t.
This audit is the first thing I do on every account I take on. If you’d like it done for yours, get in touch.