Hoover Institution

How increasing landing page congruence affects cost per subscriber

Experiment ID: #314

Hoover Institution

Experiment Summary

Timeframe: 12/01/2014 - 12/25/2014

The Hoover Institution wanted to add new subscribers to its highly-regarded military history and foreign policy newsletter Strategika. Facebook ad targeting allowed them to find new subscribers by targeting these specific interests, but after a few weeks of the campaign, cost-per-subscriber was still higher than original projections.

The landing page did a good job selling Strategika — it constructed a strong value proposition, showed plenty of credibility, and made a clear call-to-action that highlighted all of the benefits of subscription. But we hypothesized we could increase the conversion rate on the landing page by making a single simple change — making the landing page look more like the ad.

The ad had a historic picture of American soldiers storming a beachhead in World War 2. We changed the landing page to have this same background, and shortened the copy to fit.

Research Question

Our hypothesis was that by increasing congruence (or visual consistency) between the landing page and the ad, we could improve landing page conversion and lower the cost per subscriber.


C: Control - Strategika branded page
T1: Congruent Page


 Treatment NameConv. RateRelative DifferenceConfidence
C: Control - Strategika branded page 25.0%
T1: Congruent Page 34.8%39.2% 100.0%

This experiment has a required sample size of 163 in order to be valid. Since the experiment had a total sample size of 3,687, 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
× 39.2% increase in conversion rate
× 0% increase in average gift

Key Learnings

Not only did this new page with increased congruence convert 40% more people to subscribers, because Facebook was optimizing for converisons,  it lowered the cost per subscriber by 86% — a huge savings that allowed Hoover Institution to effectively acquire nearly twice as many subscribers with their original budget.

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

Question about experiment #314

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