Google Ads Offline Conversion Tracking — Enhanced Conversion For Leads VS ‘gclid’

TL;DR Properly implemented gclid import method seems to be ~25.79% more accurate than the new Enhanced Conversions For Leads.

The most important ideas with I've realized with conversion tracking is to never trust what anyone says. Google, Meta, online blogs or random freelancers—doesn’t matter. Different conversion tracking methods should always be A/B split tested to compare objectively which method is the most accurate.

This week, I wanted to test and find out for myself which method of Google Ads offline conversion tracking is more accurate. We have two methods: the classic Google Click ID or GCLID method and the newer Enhanced Conversions for Leads method.

The GCLID method is a pain in the ass to set up because you need a way to pass the GCLID into the conversion. So if you use WordPress and a contact form, you will need a hidden field and a JavaScript that remembers the Google Click ID as a cookie or in local storage and then populates the hidden field. And it needs to be reliable. What makes things even more difficult are iframe-based contact form widgets like Typeform, Tally, Acuity Scheduling, Calendly, etc.

To make things easier, Google has released another offline conversion tracking method, enhanced conversions for leads, where we just need to get the email or phone number from the form submission and add a user provided data tag in Google Tag Manager. Usually this is significantly easier.

So the big question is: Is the newer Enhanced Conversions for Leads method, which Google is heavily pushing and recommending, equal, better or worse?

I wasn't sure what to expect because it's not entirely clear whether enhanced conversions for leads is also using matching logged in users like enhanced conversions (enhanced conversions is different than enhanced conversions for leads!) But I was still kind of surprised to see a pretty significant difference in the performance. The classic GCLID method is clearly paired to the enhanced conversions for leads superior.

Increase in conversions is about ~25.79% which is significant.

Everything has been set up correctly. We are getting green signals. The yellow needs attention flag can be ignored. It is because we had to enable enhanced conversions for leads, but we are still using the Google Click ID. So Google is throwing a warning without any real reason.

So if you are serious about Google Ads offline conversion tracking, I would actually recommend running the A/B test yourself because this was just one website and there may be variables that vary between different websites. But this test seems to indicate that the classic Google Click ID cookie-based CRM tracking would be more effective than the new enhanced conversions for leads, which Google is heavily pushing.

Next, it would be interesting to also A/B test offline conversion tracking methods that do server-side fingerprinting, like Tracklution.