If you are going to be using cookies to tracks ads, you need consent in Europe and other parts of the world. GDPR is not always enforced but if you are using ga4 or native ads tracking with Google ads, you should ask for consent.
You can use consent mode to get a better picture of who is converting. Its better than nothing but not ideal. You can recover some of the lost conversions but it relies on Google's machine learning and you need a minimum number of conversion events for it to work.
Zapier and Offline conversions.
There is another way though and it bypasses all the cookies and GDPR (as far as I know, please confirm with your DPO). Basically, when you get a click from Google Ads, capture the gclid.
Google Click ID (GCLID) is a parameter passed in the URL with ad clicks, to identify the campaign and other attributes of the click associated with the ad for ad tracking and campaign attribution.https://support.google.com/google-ads/answer/9744275
You can get your web developer to capture the gclid and pass it along with any conversion event.
Some example Zapier connections you can use. See full list of Zapier to Ads connections.
You just need to import conversions from another source. In this example, its Woo commerce.
It will ask you to connect your Zapier account. Once you do that, you can set up a regular Zap.
You can view the PDF, Google Ads Offline Conversion Tracking with Zapier. It may work with Make or Pabbly connect too but the friendly integration is done via Zapier.
By doing this, you can track people even if they decline cookies but only if the browser doesn't strip out the gclid. I haven't seen the cost of this but I can imagine its not going to be too expensive. Even if it is, its going to be worth it to get accurate data.
Remember, everything you track should be feeding in to Google and Meta's machine learning. A few extra cents a conversion is nothing compared to what it will save you in ad costs.
This method totally bypasses GA4 and anything to do with the browser. It should be 100% accurate as long as the gclid, is not stripped out. Apple's Safari in incognito apparently does this and possibly some other browsers or ad blockers.
Using offline conversion tracking via your CRM is the optimal way to track conversions in Google ads. No cookie banners needed, no GDPR issues and few ad blocker issues (check with your DPO though). If you feel you are missing out on the source of conversions, this is definitely something you should implement.
Ben has a BEng (Hons) in Computer Science and 20 years of experience in online marketing, specialising in SEO, lead generation and affiliate marketing. After spending over a decade as an igaming affiliate, he has decided to concentrate on GA4 training and SEO Audits.