We have updated our Privacy Policy and Privacy Options

Got It

Why You Should Never Pay for a Pure Client-Side Tag Management System


Understanding the Benefits, Limitations, and Ultimate Value of a Pure Client-Side TMS

This guest post was written by David Johnson, Strategic Accounts Executive at EnsightenBrooks Bell partners with Ensighten—and several other leading testing and optimization tools—to provide the best solution for every client.

In the world of tag management systems (TMS), the prevalent model is client-side. Used by the majority of vendors, this model is easy to build, cheap to maintain and effective for basic pixel management.

Want to expand your testing program? Download our white paper and find out how!

In a pure client-side TMS, all the logic dictating when and where to deploy tags, and what data to grab from the page for tag conditions and enrichment, is defined by a set of static files that are evaluated by the browser on every page view. Want to update your tracking pixel configuration? Just regenerate those files and you are in business. IT wants to protect page performance, and they also want to host the system internally? Load the container at the bottom of the page asynchronously and host the generated files on the same infrastructure that delivers your website.

There are, however, significant downsides to a pure client-side TMS. The files that such tools push to the browser grow in size and complexity as more deployment logic is configured. Managing ten pixels and scripts on a confirmation page? Not a problem. Maintaining exception handling and reporting, event tracking, multi-level data maps across countless pages, sites and site sections? Unfortunately, that is going to include too much logic for a single client side tool to carry around and evaluate on all pages. The impact on page performance and user experience can be devastating, which is why a pure client-side tools should be loaded asynchronously, at the bottom of the page.

There are also security challenges. Since all the tag deployment logic is hosted in static files that are made available through the browser, care must be taken to ensure sensitive information is not exposed to customers and competitors.

For example, if you are launching a new campaign and have scheduled tags to be ready for launch-date, then competitors could monitor your logic files, see the updates and beat you to the punch.

In spite of these challenges, many will still be interested in trying a pure client-side TMS. Well, just as the best things in life are free, so are the best pure client-side solutions! Google and Adobe both have tag management products that will easily alleviate your pixel pain—and both are completely free (although I guess in Adobe’s case you need to be a SiteCatalyst customer, so not entirely free). The best part of these free tools is the world-class infrastructure they are based on—we are talking about Google and Adobe here after all. Paid solutions may offer better technical support programs and more canned templates for common technologies, but by and large, the free solutions are excellent, well documented and are constantly getting better.

The benefits of a pure client-side model are also available via a hybrid model like the one pioneered by Ensighten—which can even mimic the deployment and operation of a pure client-side solution, if desired. Though this option is available, none of our clients have elected to do so. Indeed, the inherit limitations in this approach have led many enterprise site managers to move away from pure client-side solutions.

Ensighten was designed to load synchronously in the HTML head, so that it can deploy any tag for any use case—always via a single line deployment that remains static, fast and lightweight under all conditions. As the logic of when and how the tags are deployed—and how data regarding segments and tag enrichment is mapped—is offloaded to our purpose-built Tag Delivery Network (TDN), none of your sensitive marketing strategies are exposed, and you benefit from effectively unlimited headroom—not to mention consistent, accelerated page performance.

A pure client-side tag management system can dramatically streamline an online marketing program—and with several good free options available, it’s a great place to start. But once you’re hooked on the power of tag management and are ready to start deploying advanced analytics, segmentation rules, testing and personalization, you are ready to see what is possible beyond pure client-side. Ensighten, of course, is an excellent option for unlocking these additional capabilities.


Need an introduction to tag management? Read What is Tag Management and What Does it Mean for Testing?