How optimizing for a purchase in Facebook affects donor conversion Experiment ID: #11550

Dallas Theological Seminary

The DTS mission is, “to glorify God by equipping godly servant-leaders for the proclamation of His Word and the building up of the body of Christ worldwide.” They strive to help men and women fulfill the Great Commission and the Great Commandment, or more simply: Teach Truth. Love Well.

Experiment Summary

Timeframe: 1/16/2019 - 1/28/2019

DTS was running a campaign on Facebook for their free Revelation online course. They typically use custom conversions in Facebook to track course signups, and Facebook shows ads to people in the targeted audiences based on this conversion. They recently discovered that Facebook has a native Purchase event that would allow them to optimize for donors, rather than course signups. This test involves a duplicate Revelation campaign where the only element changed is the conversion event- Custom Conversion vs. Purchase. 

Research Question

Do we get more donors from Facebook through optimizing for a custom conversion (Revelation Course Signup) or Purchase? 


C: Optimized for Custom Conversion
T1: Optimized for Purchase


Treatment Name Conv. Rate Relative Difference Confidence
C: Optimized for Custom Conversion 0.03%
T1: Optimized for Purchase 0.08% 191.2% 99.9%

This experiment has a required sample size of 13,451 in order to be valid. Since the experiment had a total sample size of 106,120, 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
× 191.2% increase in conversion rate
× 0% increase in average gift

Key Learnings

Optimizing for purchase targeting led to a 191% increase in donors from the Revelation campaign, as well as a 31% increase in average gift from the “purchase” campaign. This confirms our hypothesis that Facebook shows ads to more donor-motivated people when optimizing for purchases. It allows them to pull in additional purchase data from Facebook instead of relying primarily on data that we give to them (for example, a list of prospects or a lookalike audience). 

Facebook also has a native “Donate” event that we will be testing against purchase targeting for our next test to increase donor conversion even further. 

Experiment Documented by...

Allison Jones

Allison is an Optimization Associate 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.