Advertising performance
Using engagement to predict CTR
We tracked 3+ billion impressions across 2,000+ publishers on the Sovrn exchange. We then compared the relative performance of buying ad inventory based on engaged time and viewable time.
We tracked 3+ billion impressions across 2,000+ publishers on the Sovrn exchange. We then compared the relative performance of buying ad inventory based on engaged time and viewable time.
The coronavirus pandemic resulted in both an immediate decline in digital ad spend and a shifting of that ad spend to direct response campaigns. As a result, publisher ad revenue declined as well.
Currently, buyers and publishers use ad viewability as a measure of inventory quality. However, it is a flawed metric. Buyers need more accurate ways to predict campaign performance and deliver higher return on ad spend. This study demonstrates that buying inventory based on reader engagement delivers higher performance and higher return than buying based on ad viewability.
CONTEXT
As a result of the COVID-19 pandemic, we have seen immediate and noticeable changes to buyer behavior across the Sovrn exchange. We examined those macro trends, and this is what we found:
As a result, publisher revenue dropped precipitously. It became clear that publishers needed a way to offer more valuable inventory to buyers.
At the same time, buyers want better metrics that allow them to both assess the quality of supply and predict campaign performance.
With consumers spending more time online and marketers shifting spend to direct response, we need a better way to drive return on ad spend.
Measuring reader engagement with a page while an ad is in-view provides a better predictor of ad click-through performance than viewability alone.
Viewability only guarantees that an ad could be seen. It does not guarantee that an ad is seen, nor that a reader is paying attention. Past surveys1 on ad viewability have indicated that less than 50% of all impressions sold are viewable. Instead, we posit that reader engaged time is a better metric for predicting ad performance than viewable time.
In order to measure reader engagement, we identify and track reader behavior. We achieve this through a proprietary DOM event listener that tracks 40+ reader actions, such as page scrolls, mouse clicks, or keyboard activity. This allows us to effectively identify every single interaction between user in page.
We simultaneously compare these reader engagement events with both user time-on-page and the amount of time that a given ad unit is viewable. Whenever the reader is demonstrably active and the ad unit is 50% in view, this constitutes engaged time.
Engaged time ends after 10 seconds of reader inactivity, or when the reader performs a disengagement event, such as changing tabs or typing into the address bar.
Average engagement events per page view
Measured engagement types
For the purposes of this study, we elected to use click-through rate (CTR) as our performance metric when comparing engaged and viewable time.
While it is possible that there are additional or better ways to measure ad performance (e.g. brand recall surveys), CTR offers a quantifiable metric that is both understandable industry-wide and easy to use in relative measurements.
We began our study by looking at two UK-based publishers. We then recorded ad click-through rate for both engaged and viewable time over 25 million impressions. We compared CTR for 1+ second of viewable time with the CTR of 5+ seconds of engaged time.
We observed an immediate positive correlation reader engagement and CTR. 5+ seconds of engaged time yielded 20% higher CTR than 1+ second of viewable time.
Based on these initial results, we expanded our scope.
We deployed our tracking beacon across 2,238 domains within the Sovrn exchange. We then measured the amount of time that each impression we tracked was in-view and compared it to the amount of time that each impression was in-view with an engaged reader. In addition, we tracked whether or not a given impression was clicked by a user. Finally, we compared CTR between engaged time and viewable time.
In order to ensure a direct comparison, we measured both engaged time and viewable time on every impression we tracked. This ensured that the sample set was the same between both measurements. Our study surveyed a wide range of sites, from national newspapers (e.g. mirror.co.uk) to tiny cooking blogs (e.g. anerdcooks.com).
In order to verify our click tracking data, we compared our results to those provided by Google Ad Manager.
Domains
Impressions
Hours of engaged time
We observed a clear correlation between engaged time and improved CTR. When compared to viewable time, engaged time delivered an average of 2.71x higher CTR.
These results support our hypothesis that engaged time is a better predictor of campaign performance than viewable time. Engaged time therefore demonstrates a number of applications for both publishers and advertisers, and offers higher marketplace efficiency.
The most noticeable effect of this performance increase is return on advertiser ad spend. Buying 100 hours of engaged time supplies buyers with a 2.71x higher CTR than buying 100 hours of viewable time.
Similarly, studies have shown2 that brand recall rises sharply when an advertisement is in view for approximately 30 seconds. Therefore, buying based on engaged time has the potential to boost the performance of awareness campaigns, a topic that deserves further study.
Publishers with a highly-engaged audience are therefore in a position to increase their revenue. Segmenting and packaging this highly-valuable inventory delivers better results to advertisers, and should therefore command a higher price.
While these results are incredibly exciting, there are myriad opportunities to increase both the uses of engaged time and the adoption of an industry standard.
For example, initial internal studies have already shown that targeting engaged users with on-page notifications (e.g. subscription prompts) leads to improved performance. There are a number of next steps we plan to take in order to build on the results of this study:
If you're interested in leveraging your user engagement to boost your CTR and improve your ad revenue, schedule a meeting with our Growth team. We'll be happy to answer your questions and help you understand—and benefit from—the technology behind the results.
We welcome further questions and discussion from all corners of the industry. Should you want more details on the study, the technology behind it, or simply have questions for the authors, please do not hesitate to reach out.
Senior Director, Product Management
BBouquet@sovrn.com
Vice President, Product Growth
BVafaey@sovrn.com
Data Scientist
ONaughton@sovrn.com
Senior Content Strategist
JLipton@sovrn.com