The scanned URL seems to lack the inclusion of the Google Tag Manager (GTM) snippet code.
Why is this important?
Employing GTM streamlines the process of implementing tags for tracking and analytics purposes, such as for Google Analytics and Adwords Conversion Tracking.
This Optimization is simply to point out that the URL does not have a GTM tag installed.
What does the Optimization check?
Should there be an absence of the GTM code in its JavaScript or non-JavaScript form within an internal URL, this Optimization will be triggered.
Examples that trigger this Optimization
Should a URL fail to incorporate the subsequent code within the <head> section, this Optimization will be activated:
<!-- Google Tag Manager --><script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-XXXX');</script><!-- End Google Tag Manager -->
Additionally, the URL will trigger this Optimization if it excludes this in the <body>:
<!-- Google Tag Manager (noscript) --><noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXXX"height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript><!-- End Google Tag Manager (noscript) -->
Why is this Optimization marked 'Insight'?
The designation 'Insight' for this Optimization suggests it doesn't necessarily prompt immediate action. It's provided to draw attention to a potential area of interest rather than signaling an urgent issue to address.
Considering most internet sites don't leverage GTM, the typical expectation is for this Optimization to be activated across URLs where GTM isn't employed.
However, for those sites that do rely on GTM, this Optimization becomes invaluable as it will pinpoint the specific URLs lacking the GTM code, providing an opportunity for review and rectification if needed.