Firebase Analytics & GTM Tracking

Question

This question is about why one would need GTM for Google Analytics Firebase. There is a similar post on this question, but it has to do with the HOW. I am looking for the reason WHY one would want to implement GTM alongside the already powerful Google Analytics for Firebase.

In May 2017, "Firebase Analytics" was renamed to "Google Analytics for Firebase". This should not be confused with "Google Analytics" for mobile apps (legacy).

Historically, GTM was used for websites and web-apps, where one can paste the GTM snippet and "listen" for a class/id and then, for example through a tag, bind an event to that specific class/id, which would fire when clicked. This is the point where it becomes a bit confusing... I thought one would be able to remotely implement a custom event in GTM, but as far as I understand, GTM works only in parallel after the Firebase custom event has been implemented at the specific point where you want to track the event (i.e. button).

• "Google Tag Manager uses Firebase Analytics' events, parameters, and user properties to trigger and build tags you've configured in the Google Tag Manager web interface. In this sense, your Firebase Analytics implementation acts as your data layer" (source),
• "Firebase event name variables, Firebase event parameter variables, and other variables are used to set up triggers. Trigger conditions are evaluated whenever you log a Firebase event. By default, Firebase Analytics events" (source).

GTM has always been marketed as "remotely configure your tracking", but unless I am missing something, it seems that you in anyway need your developer team to do a custom implementation on each and every event you want to track and thereafter do the GTM set-up for extra benefits, like:

• Configure variables in Tag Manager: i.e. Change an event's parameter value after the app has been deployed, without the need to re-upload your app to the app/play store.
• Modify and block Firebase Analytics events (assuming those custom events have already been implemented).
• Fire Tags: i.e. Send the exact same events to Basic GA (that were triggered for GA Firebase), if you want to use that as well.
• Preview, debug, and publish your container (Note: GA for Firebase has already Debugview for debugging).

I have however seen in the GTM console that one can "Add Event" for the Google Analytics (Firebase), but I have not really seen any solid examples out there of how it works.

I am not a GTM expert at all, so unless you want to:

• Do more advanced 3rd party ad-tracking,
• Send events to your own data-warehouse,
• Have the same events in Basic GA as in GA for Firebase

I don't see the direct impact that GTM holds if one has to first implement the Firebase Analytics events directly in the code-base in anyway.

My Questions:

• Can one set up custom event tracking from within GTM before explicitly adding custom Firebase events at each and every button within the code-base ?
• If yes, can someone please share actual examples of this dual GTM and GA for Firebase implementation ?

Thanks!

Answer 1

Here are the primary reasons as to WHY someone would use GTM with Google Analytics for Firebase.

• GTM acts as a bridge in between Google Analytics and Google Analytics for Firebase. If you want the Firebase data to go in same GA property then GTM is the only option.
• GTM intercepts Firebase events. This gives an advantage to the developer if he/she want to make efficient use of the 500 events restricted by Firebase framework by modifying the current events if they are to be used for other purpose going forward.
• Answer for you question about custom event come from the "Add Event" tag type. Add Event is used when you want to create a second event from the source event. For example, if you're already logging button clicks, but want to treat a button click on a specific button as a custom event as well, you would setup a tag as an 'Add Event' tag, and trigger it when a button click event happened with parameters matching the specific button name.