How an email written at a 9th grade reading level impacts click-through rate
Experiment ID: #175530
American Cornerstone Institute
Experiment Summary
Timeframe: 04/12/2024 - 04/26/2024
ACI was launching a new pledge to their housefile. While writing copy for this offer, we wondered if writing the copy at a lower reading level would impact click-through rate. We typically write copy at a 12th grade reading level for this client’s offers. For this experiment, we tried writing copy at a 9th grade level.
Research Question
We believe that writing copy at a lower reading level for people on ACI’s housefile will achieve a higher click-through rate because it will be easier for people to read and comprehend.
Design
C: 12th Grade Reading Level
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Results
| Treatment Name | Click Rate | Relative Difference | Confidence | |
|---|---|---|---|---|
| C: | 12th Grade Reading Level | 1.3% | ||
| T1: | 9th Grade Reading Level | 0.85% | -33.7% | 99.9% |
This experiment has a required sample size of 4,344 in order to be valid. Since the experiment had a total sample size of 25,834, 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:
33.7% decrease in traffic
× 0% increase in conversion rate
× 0% increase in average gift
Key Learnings
The key learning from this experiment is that writing copy at a lower reading level for people on ACI's housefile did not result in a higher click-through rate. In fact, the treatment group, which received the copy at a 9th grade reading level, experienced a 33.7% decrease in clicks compared to the control group that received the copy at a 12th grade reading level. This outcome was statistically significant with a 99.9% level of confidence. Moving forward, it is important to carefully consider and test hypotheses before making changes to copywriting strategies. While the intention was to make the content more accessible to readers, the results showed that the original approach might have been more effective in engaging the audience. Future experimentation should focus on testing different variables and closely monitoring the outcomes to make informed decisions about optimizing copy for better performance.