Modern ad platforms are optimisation machines. Google, Meta and TikTok all use the conversions you send them to decide who sees your ads and how much to bid. That is powerful when the data is right and expensive when it is wrong: the algorithm learns from whatever you report, so broken tracking teaches it to find more of the wrong people.
Before you increase budget, spend a week making sure the numbers can be trusted. Here is the order we work in.
1. Decide what a conversion really is
Write down the actions that matter to the business: a purchase, a qualified lead, a booked call. Then list the small steps along the way, such as a form started or a pricing page viewed. Only the first group should be primary conversions that the platforms optimise towards. Everything else is useful for analysis but should not be counted as a win.
2. Remove double counting
The most common problem we find is the same conversion counted twice: a thank-you page that fires on every reload, a purchase tracked by both a plugin and a hand-added tag, or GA4 and the ad platform each counting the same lead. Test every conversion yourself and check that it fires once, with the right value.
3. Compare the platforms with reality
Put the numbers side by side for the same period: orders or qualified leads in your shop or CRM, conversions in GA4, and conversions in each ad platform. They will never match exactly, because each tool attributes differently, but big gaps point to tracking problems rather than attribution differences.
4. Send data from your server, not just the browser
Browser-based tracking misses conversions because of ad blockers, privacy settings and cookie limits. Server-side options – such as Meta’s Conversions API and Google’s enhanced conversions – send the same events from your server or tag manager, matched with hashed customer details. Set them up with de-duplication so each conversion is still counted once.
5. Respect consent
In the UK and EEA you need a consent banner that actually controls your tags, and Google requires Consent Mode signals for personalised advertising there. Implemented properly, consent mode keeps you compliant while letting the platforms model some of the conversions from people who decline.
6. Feed back what happens after the click
For lead generation, the form fill is only the start. Import later stages from your CRM – qualified, proposal, won – so the platforms can learn which leads actually turn into revenue. Even a weekly upload makes a difference.
7. Check it every month
Tracking breaks quietly: a site update removes a tag, a checkout app changes, a form is replaced. Put a monthly reconciliation in the calendar and test your key conversions after every website change.
The short version
- Optimise only to conversions that matter to the business
- Test that each one fires once, with the right value
- Reconcile platform numbers with your CRM or shop
- Add server-side events with de-duplication
- Use a consent banner and consent mode where required
- Import offline outcomes so platforms learn what quality looks like
Our paid advertising audits start with exactly this, because every other improvement depends on it.
