white paper how tag management improves web...

© 2015 Tealium, Inc. All rights reserved.

WHITE PAPER

How Tag Management Improves Web Site Performance Best Practices for Reducing the Impact of Third-Party Tags

June 2015

How Tag Management Improves Web Site Performance 2

Table of Contents

Performance Improvement Methods ....................................................................................... 3 Conditional Loading ........................................................................................................................... 3 Asynchronous Loading ...................................................................................................................... 5 Reduced Page Weight ....................................................................................................................... 6 Reduced DNS Resolutions ................................................................................................................ 6 Script Compression (gzip) .................................................................................................................. 7 Client-Side Tagging with no Application Server Calls ......................................................................... 7

Case Study: Fingerhut .............................................................................................................. 8

Conclusion ................................................................................................................................ 9


Web site performance matters. According to a study by Aberdeen1, a one-second delay in page response can result in a seven percent reduction in online conversions.

Many factors impact site performance, including the speed of the hosting provider, page design, number of http requests, and more. One big factor is the accumulation of digital marketing vendor tags and pixels on web pages. Tags can dramatically impact site performance in a number of ways, including poor tag design, slow response time associated with the collection servers, tag placement and the sheer number of tags accumulated on pages.

Over the years, Tealium has pioneered many of the best practices in tagging and has incorporated various techniques to minimize the effect of tags on web site performance. They include:

• Asynchronous tagging • Conditional loading of tags • Reduced page weight • Reduced DNS resolutions • Tag compression • Client-side tagging with no application server calls

This white paper provides more details about these techniques and their associated benefits.

Performance Improvement Methods

Conditional Loading A cornerstone of any enterprise tag management solution is the ability to conditionally load tags based on select criteria. Within the Tealium iQ™ tag management system, these are known as load rules. These conditional load rules can be used to reduce the number of times tags are loaded and eliminate the redundant pixels. Examples include:

• Loading of tags based on source of traffic: For example, customers can set rules to load a Google AdWords tag on the confirmation page only if the traffic originated from an AdWords campaign.

• Loading tags only once: Many tags need to be loaded only once during a session or per visitor. For example, if you’re launching a retargeting program for the shoes section of the site, you only need to launch the retargeting pixel once.

1 Simic, Bojan, “The Performance of Web Applications: Customers Are Won or Lost in One Second” November 2008, Aberdeen Group


To demonstrate this capability, consider a web site leveraging five different vendor tags on its confirmation page (Figure 1). In this example, all five tags (or pixels) will load on the confirmation page regardless of the source of traffic.

Figure 1. Tag loading without conditional load rules.

Conditional loading, on the other hand, lets you decide under which circumstance to load each tag on the confirmation page. As a best practice, you can create rules that let you load the AdWords tag on the confirmation page only if the source of traffic is Adwords (Figure 2). You can create similar conditional rules for other marketing tags.

Figure 2. Tag loading with conditional load rules applied.

Conditional loading of tags offers two advantages:

• It improves page load time by dramatically reducing the number of pixels being called from the page (from five to one in our example).

• It puts marketers in total control as to how and when they share critical data (e.g., transaction data) with third-party vendors. Rather than sharing all transactional data with all vendors, marketers can now share data on a “need-to-know” basis.


Asynchronous Loading One of the many ways Tealium iQ improves site performance is with the asynchronous loading of tags. This method is becoming increasingly popular, especially after Google’s adoption of asynchronous tags in 2010 for its analytics product. Tealium is one of the pioneers in asynchronous tracking, first adopting the methodology in tag management back in 2008.

But what exactly is asynchronous tracking and how does it improve site performance?

Before explaining the asynchronous method, it is important to note how vendor tags load and why they slow down web sites. Most tags today are loaded in a linear fashion, one after the other, serially instead of simultaneously. This is known as synchronous loading. When a page loads a synchronous tag, it waits for the tag content to load before moving on to the next tag. The figure below shows an example of a page loading four tags in a synchronous or serial manner. The page starts by loading the first tag. After the tag has been completely loaded, the page moves on the second tag. The process is then repeated for the ensuing tags. Assuming each tag takes half a second to load, we’re looking at a total load time of two seconds to load all four tags.

Figure 3. Synchronous tag loading.

With asynchronous tracking, the browser can load the different tags in parallel. It no longer has to wait for a certain tag to load completely before moving on to the next or the rest of the page content. This is shown in the figure below. Using our example of the page with four tags, we can see that the browser starts downloading the four tags in parallel, completing the process much faster. The four tags in this case are completed in a fraction of a time compared to the synchronous method.


Figure 4. Asynchronous tag loading.

Asynchronous tracking has many benefits. One obvious benefit is improved site performance (Figure 4). Another benefit is improved tracking and data accuracy. Because tags are loading in parallel to the rest of the content, they can be placed on top of the page, which improves the accuracy of data being collected.

Reduced Page Weight A low-hanging fruit in page optimization is the reduction in page weight. This is accomplished by replacing all vendor tags with a single tag. A typical Adobe SiteCatalyst implementation, for example, may consist of about 2KB of page code on each page, not including the SiteCatalyst JavaScript file (referred to as s_code.js). For a web site averaging 10 page views per session, this translates to 20KB in page code savings during each session. The page code replacement results in substantially smaller footprint, which helps load pages faster.

Reduced DNS Resolutions In addition to lowering the page weight associated with tags, Tealium also reduces the number of DNS resolutions associated with the serving of tag libraries. This is because libraries are now hosted from the same domain. This is applicable whether you’re using the on-demand or on-premise version of Tealium iQ.

For example, say a site is using Google Analytics, Yahoo! Web Analytics, ClickTale and ClearSaleing on the same web page. However, with Tealium iQ, all four libraries are hosted on the same domain, reducing the number of DNS resolutions from four to one.

In traditional tagging, all four solutions need to download their respective JavaScript libraries from four different servers, making four distinct DNS resolutions. Each DNS resolution results in the download of just one file, which is very inefficient.

Using Tealium iQ, all four libraries are hosted on the same domain, reducing the number of DNS resolutions from four to one.


Script Compression (gzip) Because Tealium iQ also manages the serving of JavaScript libraries (whether from content distribution networks or your own servers), it has the ability to optimize JavaScript libraries using a number of best practices. One way Tealium optimizes the JavaScript libraries is by compressing them using the gzip compression format.

Compression is a simple and effective way to speed up web sites by saving bandwidth and reducing the data transfers necessary. In one instance, a big retailer of auto parts using IBM Coremetrics was able to reduce the size of its JavaScript file by a factor of six.

Compression allows required libraries to be transferred at a fraction of the time compared to traditional tagging. Because files are downloaded faster, tags execute faster, providing both improved performance and more accurate tracking.

Client-Side Tagging with no Application Server Calls Tag management should not get in the way of tagging. This is our core belief and it’s the foundation upon which Tealium is built. However, many tag management solutions are built on a flawed architecture that gets in the way of tagging, which impacts site performance, accuracy, redundancy and scalability of the solutions. Although this is an area where Tealium does not necessarily outperform traditional tagging, it clearly outperforms other tag management solutions. To understand why, please see the figure below.

Figure 5. Tag management with minimal server calls.

In this example, we’re looking at a session (or visit) consisting of seven page views and running two web analytics solutions (say SiteCatalyst and Webtrends). When the visitor lands on page 1 (the landing page), the solution hits a file server to download the main JavaScript file. The JavaScript file can then determine that the two analytics tags are required and makes another request to the file server to download the appropriate libraries or tags. We therefore have two requests to the file server on the initial page.

On each ensuing page (pages 2-7), the libraries associated with the two analytics tools are already available as they’re cached within the browser. As the visitor goes from one page to next, there’s no requirement to load any additional libraries and therefore no additional connections or server calls are made. This method is optimal, scalable, eliminates unnecessary server calls (or "round trips"), and it's ideal for heavily trafficked web sites.


It is also important to note that Tealium leverages a unique multi-CDN approach that leverages the fastest CDNs in the world to serve its clients’ tags. Tealium monitors CDN performance every 10 minutes and serves its tags from whichever CDN is performing best in any given region, at any given time.

Now let’s consider the alternative, which is shown in the figure below.

Figure 6. Tag management with unnecessary application server calls.

We are going to assess the same session with seven page views using an inefficient tag management solution. In this case, when the visitor lands on page 1 (landing page), the solution hits a file server to retrieve the main JavaScript file. The JavaScript then makes a server call to an application server. The application server determines which corresponding files need to be loaded and sends instructions back to the visitor’s browser. The visitor’s browser then sends a request to a file server to download the necessary tag libraries. In this method, the solution has introduced an unnecessary application server call within the process.

On each ensuing page (pages 2–7), the original library makes a call to the application server to determine which additional files are needed. The application server sends back a request with the location of tags needed. But this time, because the tags have already been downloaded, the browser can retrieve the necessary libraries from the cache. In this method, the browser has to make an additional server call to the application server on every single page. This method introduces a point of failure. The additional steps impact scalability, reliability, and create a subpar system. Tag management is in the way.

Case Study: Fingerhut Fingerhut.com uses a variety of online marketing solutions, each of which requires the company to place a tag on a web site. These solutions are critical for maximizing online results but over time, as the number of solutions has grown, the preponderance of tags began to affect the speed and performance of the web site, especially through the checkout process. Because web page speed is so critical in keeping visitors engaged and moving through checkout, Fingerhut began to research tag management solutions, and quickly found Tealium.


Fingerhut deployed Tealium iQ throughout its site and noticed an immediate increase in web site performance, including a 49 percent increase in page load speed through the checkout process. The company attributes this to Tealium’s conditional and asynchronous tag loading techniques, both of which vastly improved site velocity.

Conclusion Over the years, Tealium has provided tag management for some of the most demanding brands worldwide, and has developed a number of best practices for improving site performance. The Tealium performance advantage is the result of using a combination of best practices, not just one.

In addition to improving site performance, Tealium allows organizations to easily manage their marketing vendor tags. Using Tealium iQ, marketing and business professionals can easily add, delete and edit marketing tags and pixels in minutes using the point-and-click interface. The solution allows businesses to save time and money while improving marketing results and site performance.

"Tealium increased the performance of our web sites almost immediately. Tealium’s impact on the checkout process was particularly impressive, increasing page load speed by 49 percent. We are thrilled with Tealium and the results they delivered." – Mark Redetzke, vice president, ecommerce and digital marketing, Bluestem Brands

About Tealium Tealium is the leader in enterprise tag management and customer data solutions that power the real-time enterprise. Tealium’s customer data platform, comprised of tag management, data management, and enterprise data services, enables organizations to connect and manage all of their marketing applications and fragmented data sources. Tealium helps marketers easily create composite 360-degree customer profiles; drive more profitable omnichannel interactions; and fuel the performance of enterprise data warehouse projects.


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Tealium has offices worldwide. Phone numbers and addresses are listed on the Tealium web site at tealium.com/contact.

© 2015 Tealium, Inc. All rights reserved. Tealium, Tealium iQ, AudienceStream, and all other Tealium marks contained herein are trademarks or service marks of Tealium. All other marks are the property of their respective owners. Rev. 060515

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