How adding suggested gift amounts affects donor conversion

Experiment ID: #930


CaringBridge offers free personal, protected websites for people to easily share updates and receive support and encouragement from their community during a health journey. Every 7 minutes, a CaringBridge website is created for someone experiencing a health event.

Experiment Summary

Timeframe: 02/01/2015 - 02/17/2015

CaringBridge had 3 suggested gift amounts on their donation page for as long as anyone could remember: $70, $125, and $300. These numbers had been tested in the past, but no one on the current team had any reference point for their selection. Data showed that a large number of donors used the “other” field to enter their gift amount (mostly lower gifts around $20). We thought that increasing the number of suggested amounts might decrease decision friction and increase conversion rate for those who wanted to give, but thought that the initial ask was too high. Our only fear was that we might lower average gift by lowering the initial ask, so we hoped that the increase in conversions made up for the perceived decrease.

We launched a new treatment with 6 giving options: $25, $50, $75, $100, $250, and $500, as well as the other field.

Research Question

Will increasing the number of options on the donation form increase the number of conversions?


C: 4 Buttons
T1: 6 Buttons


  Treatment Name Conv. Rate Relative Difference Confidence
C: 4 Buttons 0.96%
T1: 6 Buttons 2.0% 104.4% 98.7%

This experiment has a required sample size of 1,308 in order to be valid. Since the experiment had a total sample size of 4,159, 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
× 104.4% increase in conversion rate
× 0% increase in average gift

Key Learnings

The increased choice led to a 104.4% increase in donor conversion. Additionally there was only a $4 decrease in average gift (which was not significant or valid), so there was a significant increase in revenue overall as well. This suggested several other tests to erase the dip in average gift and maintain conversion, but was immediately rolled out to other forms on the site.

Experiment Documented by Jeff Giddens
Jeff Giddens is President of NextAfter.

Question about experiment #930

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