5 November 2025: Analytics Summit 2025, Hamburg
In the new version of Google Tag Manager, auto-event tracking has received a considerable usability upgrade. It might seem quirky at first, especially if you’re used to the old auto-event tracking method, but the logic behind the new setup is brilliant. The most important distinction is that auto-event tracking isn’t something you control with separate tags anymore. Rather, it’s now entirely trigger-driven, meaning you activate and specify the auto-event tracking of your choice using tag triggers (triggers are what ye olde folk used to call rules).

Continue reading

X

The Simmer Newsletter

Subscribe to the Simmer newsletter to get the latest news and content from Simo Ahava into your email inbox!

The User ID is definitely one of the coolest things about Universal Analytics, if used correctly. It might reveal some surprising insights about your visitors, since now you’re not restricted to analysing visitors as just browser or device instances as before, but rather you can build your stories around all the touch points the user might have had on their journey to and through your web properties. With this simple tip, you can extend User ID tracking to return users without them needing to authenticate.

Continue reading

I’ve written a completely revamped version of this toolset for Google Tag Manager V2. Well, I just yesterday published the first of my GTM API tools (the Container Visualizer), and I vowed that I wouldn’t release the other tools for a number of reasons. The reasons were good, in my opinion (especially the part about the tools being ugly as crap), but on the other hand I don’t want to keep anyone away from the amazing potential of the new API.

Continue reading

[UPDATE:] Quite a lot of people had trouble accessing the tool after I published this post. This should now be fixed. So, AWESOME stuff. The new Google Tag Manager UI and API have just rolled out, and I can finally start revealing the stuff I’ve been working on :) I’m not going to go into the new UI in this post. I just want to give a huge thanks to the GTM team for working on the UX with such dedication.

Continue reading

Here’s a tip on how to avoid a horrible, horrible mistake with Google Tag Manager. Tip 7: Always use .push() with dataLayer When you assign a value to a variable using the equals ( = ) sign, you are actually reallocating the variable to a new value, and the garbage collection system of the runtime environment sweeps the previous value to bit heaven. Let’s put it simply: if you redefine dataLayer after the GTM container snippet, you will break GTM’s proprietary functions.

Continue reading

I’ve noticed that setting up eCommerce in Google Tag Manager (and now the new Enhanced ecommerce) is very difficult for many. I’m sure part of the problem is that eCommerce is for many users the moment that GTM forces you to take steps in to the developer’s domain, since it’s obvious that you’ll need to add some code to the web page. This isn’t a tutorial on how to do eCommerce in Google Tag Manager.

Continue reading

This time we’ll take a look at two different, JavaScript-y features of Google Analytics and Google Tag Manager. Callback as a concept should be familiar to anyone who’s ever used a programming language. It’s basically a piece of code that is passed as an argument to some function, so that when this second function has completed, the callback is executed. For web analytics, callbacks are hugely important, since they allow you to impose a firing order for your asynchronous tags.

Continue reading

Author's picture

Simo Ahava

Husband | Father | Analytics developer
simo (at) simoahava.com

Senior Data Advocate at Reaktor

Finland