Google Tag Manager (GTM) has been one of my favourite topics of conversation over the last couple of years. In fact, most of my recent blog articles have focused on it - including a specific guide to setting up Google Tag Manager and how to setup scroll tracking.

However, what is important to cover is the actual reasons as to why you should be using GTM.

Universal Analytics has been out of beta for a couple of years now, so if you haven't upgraded to Google's most recent iteration of Google Analytics, you should consider using Google Tag Manager to complete the implementation - and the above guide can assist with this. It’s worth noting that GTM has a new user interface (UI) that can be found here, but first, let’s cover off what tags are.

What are tags?

For the uninitiated, I'll (try to!) provide a very simple definition. Essentially, tags are snippets of code - usually javascript - that execute a specific function on your website. For example, the Google Analytics snippet is a tag.

Tags also enable you to measure the impact of advertising on your site, use remarketing and retargeting, and much more. But why should you use a tag management system?

Why should you use a tag management system?

Tagging can get pretty complex. Larger websites in particular can have lots of tags or code snippets that need to be added, require updating regularly or have complex installations, but it’s not just the complexity involved, and there are several other reasons why you should use a tool to manage all your tags - and in particular Google Tag Manager.

1. GTM is free and future proof

Tag management systems are not a new invention - they've been around for a few years now - but most of them charge a fee for the use of the product. Google's is free, which makes it very appealing. It's very similar to Microsoft's tactics during the ‘Browser Wars’ of the mid-90s. Give something away for free and leave the competition redundant.

Seasoned computer users will know how well that turned out for Microsoft, but Google won't make that mistake. If there's one thing they won't do, it's get lazy with their product. I believe they are acutely aware that marketers and business owners need a way of easily managing and updating their tags/code snippets without touching the code.

The iteration released by Google nearly two years ago is testament to that, refining the terminology so that ‘technophobes’ can understand the semantics. But the fact that it’s free and future proof isn't the only reason why GTM is the best thing since sliced bread (slight exaggeration).

2. Ease of use

Within reason, Google Tag Manager enables you to insert a piece of code once, without ever having to bother your web developer. This is perfect for teams with an external web developer because you are not repeatedly asking that developer to make changes. For in-house teams it also means your developer can focus on improving the website, as opposed to making changes to benefit your data, thus streamlining the process.

It also means that if you need to update any of your tags (remember what I said earlier about upgrading from Classic Analytics to Universal Analytics), you can do this yourself by updating the tag in the GTM dashboard.

3. Pre-defined tags

Google is well aware that the majority of websites use a similar selection of tags. This isn't just limited to Google Analytics or AdWords Conversion Pixels - it also includes other tags used for remarketing purposes such as:

  • DoubleClick;
  • Marin;
  • comScore.

This is perfect for marketers who aren't familiar with code. The GTM snippet is inserted once on all pages, and all tags are inserted into pages that the rules (now known as ‘triggers’) associate with the designated tag. What’s more, Google announced support for a wide range of new tags, including HotJar and Bing Ads.

You can find the latest release notes for GTM here, as well as their full list of supported tags.

4. Debug mode

Google Tag Manager also contains an option to test your tags before you publish them.

Data accuracy is becoming increasingly important (and increasingly difficult given the web spam issue), so being able to try out your implementation to ensure your tags are firing correctly is hugely important. This ensures it never affects your live data.

It’s best to review Google’s help docs on this subject, but it’s pretty easy to get to grips with.

5. Version control

Whilst the debug mode is great, sometimes errors do occur that may be beyond your control (think of that pesky web developer who changes the code without consulting the marketer/analytics expert). GTM is prepared for such occurrences and utilises version control, enabling you to rollback to previous versions and keep everything really organised. It can also help you implement similar installations on new GTM containers as it lists all the tags that you have implemented in that particular version.

6. Environments

A (relatively) new feature in GTM is environments.

Environments enable you to control your tag manager installation across live/production websites or apps, and their development/staging counterparts.

Similar to both debugging and version control, this tag manager feature enables you to publish your tags to different environments, for example a testing server, so you don’t affect or change your live version when publishing. You can then share preview modes with others to further test your installation - incredibly useful for those more complex installations.

7. User control & permissions

In a similar vein to Google Analytics, the application allows you to have control over who can access your setup and how much they are allowed to do within GTM. These permissions start at the ‘view only’ level, and then you can enable ‘Edit’, ‘Delete’ or ‘Publish’ permissions on a per container basis.

Within accounts (comparable to an account in Google Analytics) you can then set either ‘View only’ access, or ‘View, edit and manage’ access.

8. Improving user experience

How can a tag management system improve user experience? Well, it can do this both directly and indirectly. Its direct impact is improving site speed.

Site Speed

Say you have several tags on your website. This results in more code to load, and potentially a slower page load time. You could even have tags on your site that are old and no longer in use.

Tag management systems only load the tag container snippet, and all the tags are housed within the snippet. You can then manage your tags all from one location (the dashboard) and speed up your site.

There are caveats to this - too many tag snippets can cause load time issues, for example - but generally, GTM should improve site speed performance.

The indirect effect on user experience comes from further implementation, which I’ll explain below.

Event Tracking

Recording events on websites is nothing new. For the those who are unfamiliar with the concept, it involves custom javascript code that you would add to a website to track events like clicks, form submissions, video engagement, and embedded map usage. Google Tag Manager comes with event tracking built in - otherwise known as auto-event tracking.

The term ‘auto’ is, in truth, a bit of a stretch. There is still some setup required, but it is relatively straightforward to do. I won’t cover that tutorial here, but the basic events that you can track are based on:

  • clicks;
  • form submissions;
  • link clicks;
  • time specific.

You can also create custom events that record things such as scroll depth.

Why is this important? Well, fundamentally it enables you to gain insight into what actions users undertake on your website. Are they clicking on certain links? Are they engaging with the content? Are they completing form submissions? You can then use these events to create goals specific to your business in Google Analytics.

And finally

I (still) think Tag Manager could well be one of Google’s next big pushes. With recent developments around the launch of their range of free analytics-related products, such as Google Optimise, the installation of these tags will become even more important. After some of their experiments that have not performed so well (the death of Google Authorship in search results springs to mind), I believe GTM to be a winner.

People need analytics. People need data. People need tools that can save them time or streamline the little resource that they have. That’s why GTM works so well. It’s not the perfect tool just yet, but they will keep improving things.

If you’d like to check out some more resources on Google Tag Manager, the two I’d recommend are Simo Ahava’s digital analytics blog, and Justin Cutroni’s too.

Editor's note: This post was originally published in February 2015, and has been updated to reflect the latest Google Tag Manager updates.