When a Bounce Rate is Too Low: A Lesson in Google Analytics

I have designed, managed, and consulted on websites for over a decade now. Accurate data is essential to understanding your audience and how they are interacting with your digital content, and I’ve had no reason to question the reports I’ve gotten from Google Analytics until recently.

I consult with a collaborative digital resource project for a number of communications needs, and we recently had a call about website metrics. The report appeared mostly normal, until the last statistic: the bounce rate.

To be honest, I usually find bounce rates to be fairly forgettable. In my experience these stats usually stay fairly consistent within a health range of 40-60%. The site with the best bounce rate I’ve seen recently (for Equal Access Legal Services) reports a respectable 33-45%. But this collaborative digital project? They reported a bounce rate of 0.9%. Zero point nine percent.

What is the bounce rate?

Before we delve any deeper I want to define bounce rates. Bounce rate is the percentage of visitors to a particular website who navigate away from the site after viewing only one page. Google Analytics uses pageviews to calculate bounce rate. If a user visits your website and then leaves the site without clicking any links or interacting with any content, that’s a single pageview and a bounce. If that user instead clicked a link and opened a second webpage on your site before leaving, that’s two pageviews and no bounce. A high bounce rate (>70%) is a sign that your site isn’t retaining visitors, and your should adjust your digital strategy; however, it’s also a bad sign when your bounce rate is too low (<10%).

The Investigation

A good bounce rate is a like a good golf score; lower is usually better, but a bounce rate of 0.9% is like a golfer telling you they hit 18 hole-in-ones in a row. He’s lying.

I had a decade of web experience telling me that a 0.9% bounce rate was wrong, but I didn’t know why it was wrong. Why would a standard analytics report show that out of thousands of users nearly none of them had bounced? Was it at all possible that our digital marketing was just that good at micro-targeting our audience? Of course not. We’re good, but no one is that good.

My first instinct was that there was a reporting error with Google Analytics, but I didn’t manage the account directly so I couldn’t check the settings or filters. Double-checking the data I noticed a steep drop in bounce rates several months back. It had been relatively low before, but seemingly overnight the site’s bounce had virtually disappeared. I next noticed that our pageviews per session seemed a little high. It hadn’t been the first thing I noticed, but looking a little closer I hypothesized that we’d see a spike in pageviews that correlated with the sudden drop in the site’s bounce rate. That would be clear evidence that there was a configuration error in Google related to an update several months prior.

I was developing a theory and had some evidence, but still didn’t know the source of the problem. A quick Google search confirmed my suspicions, but still didn’t tell me exactly what was happening on this site. It’s clear that there’s a problem with the Google Analytics reporting, but there could be multiple causes.

To test this theory I opened Chrome and downloaded / installed the Google Tag Assistant extension. I opened the website, and enabled the Tag Assistant. I found my answer immediately. The extension indicated an error with Google Analytics on the site, reporting: “2 Pageview Requests: Same web property ID is tracked twice.” Mystery solved.

Conclusion

I reported my findings to the website manager and they quickly identified the problem: Google Analytics and Google Global Site Tag were both reporting a single pageview to Google Analytics. The result was the system recording every single view as two, a formula that would eliminate bounce.

As I investigated this odd data point I ended up reading about bounce rates more than I have in the last decade combined. Ideally, we want low bounce rates. I want to know the content I’m creating is resonating with an audience and keeping them engaged, but when this metric is too low, it’s a red flag that there’s another problem in the system.

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