February 21, 2020
Five Ways to Do Incrementality Testing with Digital Ads
“Is my PPC Bounce Rate too high?” As an advertiser, you’ve probably asked yourself this question before. Bounce rate is not usually the primary metric that you use to evaluate your paid search program, but everyone still generally agrees that a low bounce rate is good. But what exactly defines a low bounce rate? And how do you achieve it?
Let’s start with a basic definition of bounce rate. According to Google’s definition, Bounce Rate is the percentage of single-page sessions (i.e. sessions in which the visitor left your site from the entrance page without interacting with the page). Essentially, the bounce rate tells you what percentage of total visitors only viewed one page of your site.
In order to understand your PPC bounce rate, you need to apply some context to your evaluation metrics. If you are only looking at the overall bounce rate, you are missing the real story about what is happening with your paid search visitors. Therefore, data segmentation is necessary to understand the “good” vs the “bad” when it comes to bounce rate.
Just as you have separate goals and evaluation metrics for Search and Display campaigns, you should similarly segment your data when evaluating bounce rate.
In the above example, the advertiser has an overall PPC bounce rate of 44%. When digging in further and segmenting our data by campaign type, we see that the bounce rate for Google search is very low, around 23%, whereas the bounce rate for Display campaigns is higher. This is something we see for many advertisers. Visitors from the Google Display Network are typically browsing various sites and may not be ready to receive a product pitch when they click on an ad. Visitors from Google Search ads, however, are typically looking for specific information and will more readily engage with the content on your landing pages.
The higher bounce rate for Display campaigns can also account for accidental display clicks, when searchers click on a display ad even though that was not their intent.
One more note on the above example: at 73%, there is a higher bounce rate for Shopping campaigns than Search campaigns. While this may seem high, it’s not necessarily out of the ordinary. Shopping campaigns take searchers to individual product pages, and often a searcher’s decision is to continue with the buying process by adding to cart or returning to the Google search results to comparison shop on price, shipping, or other options. A high bounce rate for Shopping campaigns is not unusual, and usually not something to be concerned about.
Even at this level of segmentation, we don’t have the full story. In order to understand the source of the higher bounce rates, it’s important that we dig in further to our device and campaign data.
Just as mobile and desktop devices drive different PPC performance, a searcher’s device can also impact aggregate bounce rate for PPC. Mobile bounce rates are often higher than that of desktop and tablet devices because mobile users are often consuming content in quick, bite-sized chunks (compared to desktop searchers who are more likely to be casually browsing or shopping). For this reason, websites with a large amount of mobile traffic will often see a higher bounce rate. Slow site speeds or difficult navigation on mobile devices can drive mobile bounce rates even higher.
Looking back to our example advertiser, let’s focus on the high remarketing bounce rate. To diagnose the cause of the bounce rate, we should segment by device. By doing so, we see that desktop bounce rate for remarketing is lower than the overall average, while mobile and tablet have higher overall bounce rates.
The last recommended segmentation for evaluating PPC bounce rate is to look specifically at campaign performance to explain the overall bounce rate. It’s easy to focus on the percentage instead of drilling down to the root cause of the bounce rate. If you see an aggregate 80-90% bounce rate, you should segment by campaign type and device, and then drill even deeper to the specific campaigns causing the high bounce rates, to analyze the precise source of the highest bounce rates.
Keeping with the above example of Remarketing performance, we drilled into the Remarketing campaigns with the highest bounce rates to see what was causing them. We immediately saw that campaigns with tiny numbers of sessions had the highest bounce rates, while high spend campaigns had much stronger bounce rates, closer to 50-60%.
A campaign with an 86% bounce rate looks bad, but if your analysis reveals that 12 out of 14 sessions bounced, and you only spent $3 over a 3 month period, you can attribute the poor bounce rate to a lack of data, and not necessarily to a problem with your website or landing pages.
The aggregate bounce rate shouldn’t be a singular cause for concern. Instead, utilize segmentation to better understand your PPC visitors’ behavior and intent. This is a much more accurate measurement of whether your PPC bounce rate is high, and if that’s actually a problem.