The Heritage Foundation

How Adding Negative Search Terms Affected CTR in Google Ads

Experiment ID: #27035

The Heritage Foundation

Founded in 1973, The Heritage Foundation is a research and educational institution—a think tank—whose mission is to formulate and promote conservative public policies based on the principles of free enterprise, limited government, individual freedom, traditional American values, and a strong national defense.

Experiment Summary

Ended On: 01/02/2020

We saw an opportunity to improve our click through rate for The Heritage Foundation in Google Ads. 

  • We saw that the Ad copy was relevant and optimized for performance however, our click through rate and search impression share was lower.
  • We observed that our brand terms for our organization overlapped with other (non-competing) organizations as a universal term that is widely used.

We ran a search term analysis Google Ads Script – N-Gram Analysis by BrainLabs that compiles the search terms into phrases to discover patterns in search terms. We then selected the phrases that didn’t meet our target performance goals and we added these phrases to our negative search terms list as “phrase match” negative keywords.

Research Question

Would adding “phrase match” negative search terms increase our CTR?

Design

C: Before Search Term Analysis
T1: After Search Term Analysis

Results

 Treatment NameClick RateRelative DifferenceConfidence
C: Before Search Term Analysis 2.4%
T1: After Search Term Analysis 12.1%392.8% 100.0%

This experiment has a required sample size of 36 in order to be valid. Since the experiment had a total sample size of 65,754, 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:

    392.8% increase in traffic
× 0% increase in conversion rate
× 0% increase in average gift

Key Learnings

Adding “phrase match” negative search terms effected the CTR by limiting the Ad showing on lower performance search terms. In addition to raising the CTR:

  • Search Impression Share increased by 17%
  • Cost Per Conversion lowered -33.59%
  • Average Cost Per Click lowered -21.80%


Experiment Documented by Riley Young
Riley Landenberger is Audience Engagement Manager at NextAfter.

Question about experiment #27035

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