How the aspect ratio of a Facebook video ad affects conversion
NextAfter
Experiment Summary
Ended On: 03/31/2020
In this experiment, we had tested into using a talking-head style video ad for some audiences in our webinar promotions. But we wondered if we could actually get more registrations by using a square cropped video, which is Facebook’s recommended video aspect ratio.
The control was the full aspect ratio video ad. The treatment was the square aspect ratio. Both videos were exactly the same in every other regard, including the subtitles.
Research Question
Will a square cropped video ad increase webinar registrations?
Design
Results
| Treatment Name | Conv. Rate | Relative Difference | Confidence | |
|---|---|---|---|---|
| C: | Full Aspect Ratio | 0.39% | ||
| T1: | Square Crop | 0.08% | -78.7% | 99.4% |
This experiment has a required sample size of 2,291 in order to be valid. Since the experiment had a total sample size of 6,788, and the level of confidence is above 95% the experiment results are valid.
Flux Metrics Affected
The Flux Metrics analyze the three primary metrics that affect revenue (traffic, conversion rate, and average gift). This experiment produced the following results:
0% increase in traffic
× 78.7% decrease in conversion rate
× 0% increase in average gift
Key Learnings
The square cropped video ad led to a 78% decrease in webinar registrations.
In analyzing the results, I wondered if the square cropped video may have gotten more engagement, but fewer conversions purely based on how much the call-to-action gets pushed down when using the square cropping. Interestingly enough, the CPM cost we nearly identical and the engagement metrics for the square video were actually lower than the full aspect ratio video.
The square cropping seemed to fall short on every metric.
One caveat that might affect the results is simply that this particular webinar promotion performed below our typical performance. But with such a significant decrease at such a high level of confidence, I’m not inclined to test this strategy any further.