The Fund for American Studies

How adding an average gift amount and minimum amount to the gift array impacts donor conversion rate

Experiment ID: #71248

The Fund for American Studies

Experiment Summary

Timeframe: 09/02/2021 - 11/14/2021

The Fund for American Studies wanted to execute a test previously inspired by a wikipedia tests that states the average donation amount (which is often a number that is not a standard, round number), and a minimum donation. The minimum donation is determined by the number of visitors to the site and the goal revenue amount for the organization. It is expected that average gift would be lower in this experiment, but it was hypothesized that the increase in donor conversion would make up for the potential loss in revenue.

This specific experiment was targeted to traffic from a specific offer that generated the most traffic (Marx Survey). Most traffic to this page is from paid social.

Research Question

We believe that adding a minimum amount and average amount to the gift array for survey takers will achieve an increase in donor conversion .


C: Control - Default Gift Array
T1: Treatment - Minimum amount & Average amount in Gift Array


 Treatment NameConv. RateRelative DifferenceConfidenceAverage Gift
C: Control - Default Gift Array 1.9%
T1: Treatment - Minimum amount & Average amount in Gift Array 2.5%29.7% 95.5%

This experiment has a required sample size of 5,095 in order to be valid. Since the experiment had a total sample size of 10,671, 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
× 29.7% increase in conversion rate
× 0% increase in average gift

Key Learnings

The final results of the experiment did provide a valid 29.7% lift in donor conversion. As expected, the average gift for the treatment was lower than that of the control. Our conclusion is that given amounts that make it relative to others’ giving habits, make prospective donors more likely to take action. However, it took several months for this experiment to validate. Should we roll this out as the control, we would need more data to ensure this is a viable strategy. It is recommended to test this on multiple instant donation pages as well as the main donation page.

Observations of the impact on other visitor segments in the experiment:

  • Mobile visitors had a 31.1% increase in donations with a 94% level of confidence.
  • Returning visitors had a 33.9% increase in donations with an 90% level of confidence.

Experiment Documented by NextAfter

Question about experiment #71248

If you have any questions about this experiment or would like additional details not discussed above, please feel free to contact them directly.