The world of web is always changing, and we are about to be dealing with an Apple Safari initiative called “Intelligent Tracking Prevention,” now in 2.0. In a nutshell, what it does is block certain forms of tracking in Safari by automatically blocking and deleting cookies. While that's good for privacy, it makes legitimate marketing efforts to give users relevant content a bit harder.

To solve some of the new issues raised by this project, last year Google released a new way to install Google's family of tracking pixels for DoubleClick, Adwords, and a few other things called the "Global Site Tag" or "gtag" for short. The early documentation out there was pretty technical, and the recommendation to install Gtag to solve all of your ad attribution problems seemed pretty compelling. The requests started flooding in. It turns out that it's not needed in all cases, and you have to read the tech docs and really understand what it is and what it's not in order to do things right.

I'm not seeing a lot of writing out there that actually understands what gtag is and when it's needed. This post is to help remove some of the confusion I am seeing surrounding the two.

Why Something New?

In the old days (internet years are shorter than dog years, so that's not really very long at all) the only way to install many ad tracking pixels was to hard code a javascript “snippet” into the HTML page code of a website. It could get pretty gnarly, especially when adding a lot of pixels and tracking complex user interactions. Back then, a developer was always needed, and this slowed things down – not because programmers are slow but because ad agencies had to figure out what all that crazy code was before they knew what to do with it. Then they sent it on to a developer, having already lost a few days in what was probably a tight schedule from the get-go. It was less than ideal and a great place to make things better.

Almost six years ago, Google introduced Google Tag Manager (GTM or Tag Manager) as a way to manage tracking tags easily on websites. GTM included a limited set of built-in tags, as well as custom image and HTML tags which allowed you to place pretty much anything. The built-in tags promised to always pull the latest, greatest code as supported by the vendor of that tag, so if you wanted a DoubleClick Floodlight Counter, you selected the DoubleClick tag and filled out a simple form. When the tag was added to the site, all of the DoubleClick javascript was built out in the best way possible. Four years ago they update to Version 2 and things got even easier.

Tag Manager also gave marketers and agencies the option of continuing to do things the old way, but without needing a programmer, by simply copying and pasting the snarly javascript into a custom HTML tag and it would run like the dark magic that it was. Occasionally, something would be wrong with the script, or a script would include a buried command for 'document.write()' but the user would not see it and, failing to check the box that said 'Support document.write', interesting things could happen like a completely white website. Fun times.

At Simpleview, we adopted Tag Manager early and along the way created a suite of tools and helped formulate the best practices for using Tag Manager. But a lot of websites out there still don't use it. Because of these non-adopters, Google came out with a new simpler platform the Global Site Tag. The naming of the new platform made the difference. Clearly, with "Global" in the name, it's got to be good. Adoption has been fierce.

What is Google's new Global Site Tag (Gtag)?

One way to look at it is that Gtag is a stripped down version of Tag Manager that can be hard-coded into a site just like the old way, but handles getting the code in the new way (just like filling out a DoubleClick form in Tag Manager). So something like gtag (...,'send_to': DC-1234567/sometype/somesrc) creates a DoubleClick tag and writes all of the javascript code to the page. It's pretty magical and solves a lot of problems needed to handle attribution in the web of 2018 and beyond. One of the other things Gtag does is to set a cookie to unify your ad tags when a user hits a site in order to change the way that Intelligent Tracking Prevention breaks tracking.

Tag Manager and gtag
But here is the thing. If you already have Tag Manager installed, you don't need or want to add gtag.js to the mix. Per Google, just use Tag Manager to handle your tags. If you are reading this and are on Simpleview CMS, then you DO NOT need Gtag because your site already has Tag Manager. But there is something you may need to do if it has not been done already.

Adding Conversion Linker?

It's a simple tag, built into Google Tag Manager which needs no configuration just add it using the All Pages trigger and publish. Done. That will handle all of you Adwords, DoubleClick and other tags already installed via Tag Manager and neatly handle everything that Gtag would do. No need to change anything else. It seems too simple but that is REALLY all you need to do.


Q: I have Google Tag Manager; do I need Gtag?

A: No, Google's DoubleClick docs say keep using Tag Manager and simply add the Conversion Linker tag.

Q: My agency sent me Gtag code mixed with DoubleClick tags. What do I do?

A: You can send that to Simpleview, and we can translate it into proper Tag Manager tags. Or you can simply inform your agency that you already have Tag Manager and simply need the Adwords/DoubleClick tags from the using Tag Manager tab. You can always send them a link to this post if they want to know more.

Q: I have legacy custom HTML or hard-coded DoubleClick tags on my site. Do I need to do anything?

A: If you still have legacy tags on your site, even if they are installed in custom HTML tags in Tag Manager, they should be updated to use the simple forms instead of custom HTML, which won't get updated when things change (like this change). That's pretty easy to do; we would be happy to show you how or we can do it for you.

I hope this helps understand a little more about the differences between Google Global Tag (Gtag) and Google Tag Manager. As always, feel free to ask more questions in the comments.