A conceptual understanding of Google Tag Manager [a review]




If you’ve been searching for a role in Growth Marketing vertical, you’d most always see a job description that requires “prior experience with Google Tag Manager”. At first, I was skeptical what could Google Tag manager possibly offer that made this skill crucial? After all, once you’ve covered Google Analytics you’re good to rule the world right? – well not exactly.


While Google Analytics is a powerful tool already to understand website flows, user behavior and etc there are things that it simply cannot provide or answer. For example: how far below did users scroll on your page, did they watch your video? If so how long? So if you’re really gunning for that Growth marketing role – you should really buckle up and learn GTM because it’s not only lifesaving – it’s also enlightening.

In this post, we’ll answer some key questions:

  • What is Google Tag Manager (GTM)?
  • Difference between GTM and Google Analytics (GA)
  • When to use GTM and when not to?
  • What can GTM do?
  • GTM is not good for?
  • What are containers in GTM?
  • What are Tags in GTM?
  • What are Triggers in GTM?
  • What are Variables in GTM?
  • What are Data Layers in GTM?


Shall we begin?


What is Google Tag Manager?


I think of it as a class A spy that sits on your website, observe and collect information like no other. In fact, it’s so good you can think of it as a spy that has the superpower to be invisible meaning able to see everything in detail that other people simply cannot (i.e Google Analytics).

So, just think of it as the best website data collection software every created to date.


Difference between GTM and Google Analytics (GA)


One word to answer this question: Depth! Yes, GTM provides more depth to the same item that you’re collecting data on. A little confused? Well, here is an example to illustrate this.




As you can visualize, the same act of visiting a page can yield more information in GTM compared to GA helping you to answer questions that require in depth details and explanations.

GTM can unleash information such as whether users interacted with specific elements on the page.


When to use GTM and when not to?


According to CXL, GA has three different functions: collect, store, and report while GTM only has one function but kills it really well : collecting it.


You’d use GTM when you’d want more granular level details that you otherwise wouldn’t be able to get in Google Analytics. If your analytics require a greater depth than using GTM is the surefire way to get a data driven answer to your problems.


Key technical tip: A key thing to remember is inserting GTM tag between the head tag and the bod tags


What is GTM not good for?

Split testing – although GTM has pretty much every possible function you can perform, split testing scripts is not an available feature within in. Use Optimizely instead.



What are containers in GTM?

Think of containers as a mini workspace that you’d want to have to individuals or teams to dabble with. If you’re a solo doer, containers probably won’t be much of a use for you. But if you have multiple teams working on the same website – you’d want to avoid instances where one team overwrites tags or changes that another team is working on.

Containers enables people to play and create changes within their own environment to experiment on before rolling out or consolidating with other teams. Another cooler reason to use containers are the version tracking that is available. Imagine, going through the log and finding out exactly which team did what – breadcrumb version history enables this.


What are Tags in GTM?


Tags basically tells GTM “go tell this platform e.g Fb, GA, or paypal what’s going on this page or website”. It basically answers where the information goes and where does it get transferred too. Another way to look at it is a glorified traffic cop that tells which information flows where.


There are two types of tags : built in, and customs. Built in tags are tags that are prepopulated and already available in the tag section of GTM, while customs require you to write your own java script to channel in the information flow.


What are Triggers in GTM?


Triggers are “when do you want GTM to flow a particular information to some other platform”.

For example, when someone clicks on this image on my website, I want GTM to tell GA that someone actually clicked on my website.


There are several types of triggers but the key ones include: page views, clicks, engagements, and others e.g Youtube.


What are variables in GTM?


Variables are a internal buzzer that pretty much answers what information do you need to do what needs to be done.


For example: if someone lands on your page, and plays the video and watches it more than 30 seconds then send the information to Google Analytics. Variables here is knowing if the video was played for more than 30 seconds.


What are data layers?


Think of it as an internal way GTM stores information. Data layers have two parts; key and value. Key are example of the subject, while values are the metrics of the key. For example:


Key: page scroll

Value: 70% of the page.


The data layer stores this information within GTM which when fired send it to the appropriate tags (platforms e.g FB, GA, and etc)


So now that you have an conceptional understanding of GTM, what are you going to do about it?


Older Post Newer Post

Leave a comment