Google Tag Manager: What You Need to Know

by Laura McKinnon

Despite being available for almost five years, Google Tag Manager - a tag management system by Google - continues to be a mystery to many marketers. Is it Google Analytics? What’s the difference? Why do we need it if we already have analytics on our site? 

If the technical jargon is confusing you, don’t worry. We’re here to fill you in on everything you need to know about Google Tag Manager!

What is Google Tag Manager?

Google Tag Manager is a free tool that can be used to store all your tracking code or “tags” in one place. It is in essence, a single container (or block of code) that sits on your website. Held within your container are your individual tags or pieces of code: 

  • Google Analytics tracking snippet
  • Google AdWords conversion tracking
  • Facebook Pixel base code
  • Custom HTML tags

The Google Tag Manager container is a single destination to help manage multiple tags - and provide a place for them all to live - an easily accessible point where you can access everything, without having to trapeze through page after page to find the right bit of tracking. 

So, what are the benefits of using it?

As a digital marketer, I’ve personally been an advocate of using a Tag Management System for years. Apart from the fact it can massively cut down on admin required to keep track of every single snippet on a site (which multiplies to the hundreds dealt with agency side.) using a tool like Google Tag Management is wonderful for reducing risk and opening up opportunities. 

Google Tag  Manager 1

Empowering Marketers

The days of sending a click event tracking request to developers? They’re gone. Using a Tag Management System like GTM opens up your tracking capabilities as a marketer, whilst reducing the burden on developers. There’s now much less of a reliance to physically go into the code on the page - Google Tag Manager’s preset variables and preset tool allows you to see all the click classes, text and more required to set the rule or “trigger” for your tag to be fired. 

It sounds more complicated than it is - and seeing it in action makes things much simpler:

Button Click Tracking in GTM

Even if not setting up your own event tracking in-house, the time it takes to set up an event through Tag Manager is significantly less than the time required for development to set up, test and roll out across your site. Less time = reduced costs. Whether you’re implementing your own tags in-house with GTM, or agency side, it’s a win-win.

Testing: 1,2,3

In the days of hardcoded analytics, one of the biggest bug bears for marketers was the inability to test a new analytics set up in a live environment without impacting existing data. 

Enter Google Tag Manager’s preview tool - a tool which allows you to test your tracking set up, before it is published live through the container. This feature alone is, in my opinion, worth the migration to the tag management system alone. 

With the preview tool, we can remove the anxiety of new tracking not working correctly. There’s nothing worse than muddied data - and GTM removes the risk of this happening as much as physically possible. The ability to preview allows you to test, test again and then some more as you make tweaks to your tracking - so no matter how complex or simple your set up, you know it’s going to work on the live site. 

Google Tag Manager 2

Roll It Back: Version Control

The scariest part of hardcoded analytics? A site update, that may be totally unrelated, has the potential to break your tracking. 

This gets back to the difficulty of managing individual snippets scattered across a site. In the case of hardcoded analytics, a sudden break in tracking can leave your team scrambling to find the error. Was it an update you made? Or is something conflicting with your tracking code? Are there any other events affected? 

Getting to the root of the problem is a challenge that can lead on into days, or in some extreme cases, even weeks, irreparably damaging your data. 

With Google Tag Manager, version control means that even if something does break when adding something new to your tracking set up, you have the ability to revert back to an earlier version of your container, to a time where tracking worked absolutely fine, meaning your data suffers minimal damage, buying you that essential time you need to debug your new tracking. 

Security Matters - A Caveat

A question asked frequently about Google Tag Manager: “is it safe?” Given that you are placing your tags within a container, with the intent to later be injected into your site, it could make you think twice about installing GTM. 

Standardised tags available through GTM from Google or approved third parties require little to no monitoring. These tags have already been extensively tested and present little to no risk. Custom HTML tags and their contents, however, allow a GTM user to add just about anything to your site. 

Custom HTML tags can be incredibly powerful - and customised to have a powerful purpose relevant specific to your site - but code that is left unchecked, can also open up a dangerous path, putting your site at risk. 

Thankfully, Google Tag Manager offers the ability to restrict and allow access, meaning enthusiastic and well-meaning users or staff can build their own tags, document the updates, do just about everything but publish, with the protection that the container can be checked by an experienced professional before being deployed to the site. 

Tag Manager, in essence gives you the same administrative capabilities as any good CMS will. Who has full access will come down to your internal policies - will you allow your third party agencies to publish on your behalf? Or will you only trust publishing to a dedicated professional? It’s a business by business case.

Google Tag Manager

Will I still need Google Analytics?

This is a question we have run into time and time again with clients - and it’s through no fault of their own. Despite having “Google” in it’s name, Tag Manager is nothing more than a tool - it in itself doesn’t track any data on your site. 

In answer, yes, you will still need to use Google Analytics - and nothing will change in how you use it. 

To use an analogy, it’s like having a filing cabinet to keep all of your paperwork. You’ll still need the content of your paperwork - a filing cabinet can’t produce that for you - but it can keep things in order, be a support - or a surface for you to doodle on, so to speak. 

How Do I Migrate to Google Tag Manager? 

Already sold but don’t know where to begin? Migrating to Google Tag Manager can be tricky for those who are not overly familiar with the tool, or indeed the technical intricacies of Google Analytics and other tracking tools. 

For every site that you plan to migrate, a plan should be created, considering the following: 

  • Are there any other updates that need to be made during the migration - for instance, upgrading from classic to universal analytics? Make sure to plan to capture this at the same time - there’s no point carrying over old or outdated technology - Google Tag Manager allows you to kill two birds with one stone - there’s no sense in doubling your workload. Group it together! 
  • What are you currently tracking? Make a list of every single bit of tracking code currently on your site: the Google Analytics standard tracking code, custom events and dimensions that you have set up, Facebook pixels, affiliate conversion codes, etc. Once you’ve made your list, find out where every bit of code appears on your site, make a note of what it is triggered by (such as time on page) and list this out. We call this a “tag map.”
  • Once you’ve created your tag map, decide whether you will build up your main container in house, or outsource to an analytics professional. If data is integral to the running of your business and you’re not too comfortable with the concept of creating and deploying tags, we recommend asking a professional to help - this is the most risky part of the migration and where, if anything can go wrong, it will! A good analytics professional will ensure nothing on your site is missed, so once the migration is complete, the transition will be seamless and there will be no noticeable loss in data. 
  • The next step: build your tags. For the likes of custom event tracking, make sure that your existing “categories”, “labels” and “actions” mirror your Tag Manager set up, so you can still compare historical data.. 
  • Confident you are good to go? Run through and test your tag map one last time - then deploy your container. The most important thing to remember is, until you have debugged and tested your container set up: do not publish your container. If you do this before you are ready and hardcoded tracking is still present on your site, then you may end up with some seriously messy and duplicated data. Try to make the time between stripping out your hardcoded analytics and publishing your GTM container as short as possible - the longer this takes, the more unreliable your data will become. 

Google Tag Manager is an incredibly powerful tool. The possibilities it opens up to marketers are plentiful. Complicated set ups like cross-domain tracking, scroll tracking and even form abandonment become a piece of cake with a very simple tool.

Getting your head around the concept of Google Tag Manager can be a challenge, but once you’ve mastered it, it is a very worthwhile effort.

Need a hand making the migration to Google Tag Manager? Get in touch - we'd be more than happy to help!