How Tag Management Failure Can Bring Down A Web Site

Single point of failure (SPoF) sounds like an aeronautical term related to NASA's Mars mission, but it's not. It refers to problems in Web site tag management systems (TMS). TagMan, which offers a TMS solution, set out to simulate multiple failures for four major airline Web sites (Virgin Atlantic, United Airlines,  U.S. Airways and JetBlue) driven by online bookings.

The tests relied on a specific method to determine whether a consumer could, theoretically, book a ticket if the site lacks a tag management system. Detecting a tag management SPoF meant diverting the TMS to a "black hole server," demonstrating what would happen to a Web site its TMS were to go down.

While one airline's Web site managed to do fairly well, three failed the test. The sites that failed could not take bookings for at least 20 seconds. The test shows Virgin Atlantic loaded correctly and allowed the ability to book flights. United Airlines produced a white page for 20 seconds until its TMS server-call timed out. JetBlue's and U.S. Airways' date pickers failed to interact when the TMS became unavailable. It didn't allow consumers to make bookings when the booking page fully loaded.



The findings show third-party content like social widgets from Facebook, Twitter and live chat are not controlled by the main Web site. Any failure to synchronize scripts or tags can disrupt the site. Sometimes it's due to a hardware failure, overload or CDN/hosting infrastructure. TagMan calls out Amazon Web Services for two failures in the past year that disrupted service for start-ups it hosted.

More than 50 U.S. Web sites tested failed the simulation, according to TagMan's white paper. Aside from airlines, it put at risk a variety of ecommerce sites like Kmart, BlueFly, Nordstrom, Sears, Tommy Hilfiger, Fox, and Fingerhut.

5 comments about "How Tag Management Failure Can Bring Down A Web Site".
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  1. michael Kaushansky from Havas Helia, August 15, 2012 at 9:33 p.m.

    Can a bad tag management solution slow down the site load time?

  2. Maggie Neuwald from TagMan, August 16, 2012 at 10:52 a.m.

    Absolutely. If the TMS doesn't load asynchronously, it introduces yet another call, which can block the page from loading until it's been fully executed.

  3. Blane Sims from Signal, August 16, 2012 at 11:06 a.m.

    Unfortunately, this article is misleading. The important point that needs to be raised here -- that 3rd-party code can potentially impact website performance and availability -- is inaccurately portrayed as a potential weakness in tag management systems. The truth is that enterprise-level tag management systems actually help protect websites from potential failures by isolating 3rd-party code from the rest of the content of the page. In most cases, this has the added benefit of providing an immediate and dramatic performance improvement for sites that adopt best-in-class tag management solutions and is among the many reasons why tag management quickly has become a best practice for the world's leading brands and ecommerce sites.

    So, to the point of this article, what happens if your tag management system has a bad day? Almost all tag management vendors allow you to load their own integration script code asynchronously, which can help isolate page content from the type of failure described in this article. Sites have different goals for their tag management systems, though, so one size doesn't fit all when it comes to script loading. The vendor who wrote this article, for example, fails to point out that its own code can be configured for use cases that create the potential point of failure that it describes. A more important question, then, is what has your tag management vendor done to harden their systems against failure in the first place? Your vendor should be able to demonstrate system availability and performance guarantees that make the risk of this type of failure less than 0.01%. Equally as important, you should have an honest discussion with all of your 3rd-party vendors about how to handle failure scenarios, no matter how remote.

    One good thing that this article does is call attention to the fact that today's websites often have complex dependencies on 3rd-party code that have become increasingly difficult to manage. This very MediaPost web page, which does not use a tag management system at all, would fail to render if Twitter, LinkedIn or its ad server aren't responding properly. My company, BrightTag, believes that the code that has 0% chance of blocking page loading is the code that the browser doesn't have to run at all. That's why we created server-direct connectivity that moves the processing out of the browser entirely, and why we're continuing to innovate to simplify 3rd-party integration.

    The bigger question beyond how simply to manage the downside risk of technical failures, is how to better manage this complexity and move beyond these fragile dependencies. Tag management is an important start down the path to a better web, but as you would with any important infrastructure decision, consider where a vendor is going before you sign up for the journey.

  4. Des Cahill from Ensighten, August 16, 2012 at 3:44 p.m.

    So let me get this straight...TagMan designed the test, TagMan conducted the test, TagMan wrote up and published the results and only TagMan's customer passed the test. Hmmm.
    Sounds fishy, don't you think?

    Unlike the "research" covered in this article - I'll be transparent and admit my bias. I'm VP of Marketing at Ensighten. Our clients like Microsoft Stores, Dell, United Airlines, Staples, etc. have great site performance and uptime. I don't need to concoct a study to prove that....

    thanks _ Des Cahill

  5. Amin Shawki from InfoTrust LLC, October 4, 2012 at 3:30 p.m.

    Hi Laurie!

    Great article about tag management and how potentially harmful it can be! I'm pretty excited about all the analytical tools assisting digital marketers and the time they save all of us. Have you heard about Google Tag Manager? It just came out and it should shake up the market big time. A problem we noticed is the time spent initially searching for those tags in your website's code, especially if you're a marketer and not a programmer. So InfoTrust created a free tool that finds tags in your website's code and generates a report of all tag locations for you. Check out, which automatically pulls tag locations for you and sends you a report. It's still in beta but we're hoping it can help with some of the headache with implementing a tag management system. Let me know what you think!


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