How increasing clarity in a Facebook ad affects clickthrough rate Experiment ID: #6008

Buckner International

Buckner International is a global ministry dedicated to the transformation and restoration of the lives we serve. We are a Christ-centered organization that delivers redemptive ministry to the most vulnerable from the beginning to the ending of life.

Experiment Summary

Ended On: 1/23/2017

Buckner International was offering a free eBook by their president, Albert Reyes, called “The Jesus Agenda”. They hypothesized that their control ad, with a photo of Jesus, might lack clarity in the prospect-level value proposition, since it didn’t show the viewer what they were getting.

They drafted three new treatments: one with the eBook and dark text, another with the eBook and lighter text, and one with the eBook right-aligned and the text on the left. They launched a four-way test to determine which one produced the highest clickthrough rate.

Research Question

Will increasing the clarity of the prospect-level value proposition increase clickthrough rate?

MECLABS Conversion Factors Targeted

C = 4m + 3v + 2( i - f) - 2a ©

Copyright 2015, MECLABS


C: Control
T1: Treatment 1
T2: Treatment 2
T3: Treatment 3


Treatment Name Click Rate Relative Difference Confidence
C: Control 0.89%
T1: Treatment 1 1.7% 95.6% 100.0%
T2: Treatment 2 1.1% 21.1% 100.0%
T3: Treatment 3 1.4% 62.6% 100.0%

This experiment has a required sample size of 2,989 in order to be valid. Since the experiment had a total sample size of 1,472,410, 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:

    95.6% increase in traffic
× 0% increase in conversion rate
× 0% increase in average gift

Key Learnings

The treatment with the dark text and the book on the left produced a 95.6% increase in clickthrough rate as compared to the control, beating the other three treatments (which also produced lifts).

This experiment shows the importance of clarity in the ad, even at the initial point of contact. The high contrast in the text makes it jump out, especially in Facebook where the majority of the platform is white. Also, leading with the book image draws the reader’s eye into the text, rather than the other way around.

This experiment will help future ad campaigns begin with more optimized design.

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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.