How the image of a membership card increased donor conversion rates through email prospecting Experiment ID: #14186

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

Ended On: 4/12/2019

As a part of the Membership Card campaign for The Heritage Foundation in 2019, we experimented with using an image of the membership card that was being offered (as a part of activating your membership) within the email prospecting channel. We wanted to see if the card would increase donor conversion rates.

Research Question

Will the membership card as a part of the email creative improve donor conversion rates in the email prospecting channel?


C: Control
T1: Treatment #1


Treatment Name Conv. Rate Relative Difference Confidence
C: Control 0.01%
T1: Treatment #1 0.01% 92.4% 97.0%

This experiment has a required sample size of 205,335 in order to be valid. Since the experiment had a total sample size of 500,345, 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
× 92.4% increase in conversion rate
× 0% increase in average gift

Key Learnings

With a 96.9% level of confidence, we successfully validated that the treatment improved donor conversion rates by 92.4% when compared to the control within the email prospecting channel.

There are actually two variables that were changed in the treatment, which were:

  1. Adding the membership card image, and
  2. Paragraph 5 and the call to action in paragraph 6 were expanded slightly.

Because of these two variables changing, we cannot definitively say that it was the membership card image that increased results singularly, however, we know that the treatment did dramatically improve results over the previous control collectively. With that said, we intend to use this treatment in the future.

Further testing with adding an image of the offer in the email prospecting channel may be warranted to singularly isolate that variable moving forward.

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Experiment Documented by...

Greg Colunga

Greg is Executive 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.