Match quality and CDN subdomain

Hello I read an article that stape wrote where they quote “ If you use a custom subdomain for your tagging server, only User IP, browser ID,
-fop, and _fbc are sent to FB CAPI. If you send only these user parameters, the match quality will be around 4 out of 10.
To have high quality score, it is pretty important to send as many parameters as possible. FB uses these data to match users on your site to the ones in their database.”

Now currently I’m using custom subdomain with global cdn. There is also an option for own cdn and disable cdn. I want the highest match quality possible so my campaigns on Facebook perform the best possible way. Which one should I choose here to have the highest possible match quality? Thanks


Is this via sGTM container or FB CAPI Gateway?

Sgtm container. My match quality is at 7.7/10 for purchase and just “Ok”

I am working on the sGTM container as well for Facebook cAPI.

The question firstly would be if that information is available on the events themselves, is your GTM set up to send user_data across to meta (and other channels)? I would look in debug mode on GTM and see what events are firing on this and diagnose the payload within the event (if that makes sense) and then check the tag/trigger/etc config’s themselves.

I am using the facebook/meta offical cAPI as well, so it might be a little different.

Yes I’m sending user data via ga4 tag. Unfortunately I don’t really know how to debug and check the payload. If it’s not too much work could you explain how to do that?

Im still quite new at GTM as well, so i would hate to send you down the wrong path but this is how I would do it…

I would load up both GTM containers, put them into preview mode and then use chrome tag manager to initiate events to debugger.

I would say that you are pushing the data.layer(user_data) which only containers firstname/lastname, customer_id and email (all hashed) so you should see that info in event viewer, from the view_item_stape for example (which is sent to the web container).

depending on your setup, I would then look at the post to facebook via the cAPI, under user_data in the request body and see what is being sent to facebook.

If your not sending anything in that (obviously log into your store account to check), then there is an issue passing the data from the store initially. If you are sending only em/fn/ln/external_id, then you arent passing additional information to facebook on that post.

which I am assuming is going to be:

If your shopify, you might need to append these records in GTM before sending to facebook.

Hope that kind of helps.

CDN has nothing to do with your match quality.

Match quality is determined by the amount of user_data, full list here: Paramètres - API Conversions - Documentation - Meta for Developers

as well as presence of fbc (fbclid), meaning the more conversions actually originate from FB ad - the better matching score (on top of user data) you’ll have.

Bottom line is, you need to send as much user data as is available during your purchase, if you’re already sending everything from the set available to you, then only further improvement is by fbc, which you don’t directly control.


I let somebody install my setup he used ga4 tag where exactly do I have to go to see which parameters I’m sending ?

in relevant GA4 tag and/or Config tag