How differing calls-to-action affect donor conversion rate across different channels Experiment ID: #8755

The Heritage Foundation

Founded in 1973, The Heritage Foundation is a research and educational institution—a think tank—whose mission is to formulate and promote conservative public policies based on the principles of free enterprise, limited government, individual freedom, traditional American values, and a strong national defense.

Experiment Summary

Timeframe: 3/23/2018 - 3/28/2018

The Heritage Foundation had tested different messaging as they sought to acquire donors with their Membership Card offer. They had tested calls-to-action with their house file who were not members, and found that “confirm your membership” led to more donations than “activate your membership”.

However, as they began to roll out acquisition with rented lists, they knew that this audience was more distant from Heritage than those who received their publications, so they wanted to re-test the CTA to make sure the result stayed the same.

Research Question

Which call-to-action will result in more donations—”confirm”, or “activate”?


C: Control
T1: Treatment 1


Treatment Name Conv. Rate Relative Difference Confidence
C: Control 0.02%
T1: Treatment 1 0.04% 79.0% 99.6%

This experiment has a required sample size of 80,415 in order to be valid. Since the experiment had a total sample size of 354,399, 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
× 79.0% increase in conversion rate
× 0% increase in average gift

Key Learnings

Both emails had a very similar clickthrough rate. But not all clicks are created equal! The CTA of “activate” produced a 79% increase in donations over the CTA of “confirm”, which was the exact opposite of how nonmembers on the house file performed. This showed that even though they weren’t members, people on the house file felt that “confirm” was more applicable to their membership status. They felt more like members—the opposite of a rented list, who felt that “activate” was the most relevant verb to their membership status.

This shows the importance of replicating tests across different channels and audiences, as they don’t all act the same way.

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Experiment Documented by...

Jeff Giddens

Jeff is a Senior Vice President at NextAfter. If you have any questions about this experiment or would like additional details not discussed above, please feel free to contact them directly.