Question 1

What is incrementality testing?

Accepted Answer

Incrementality testing is a method to measure the true impact of marketing activities by comparing a test group (exposed to marketing) against a control group (not exposed). It helps determine what would have happened without your marketing efforts, revealing the actual lift or incremental value generated by your campaigns.

Question 2

How is incrementality different from attribution?

Accepted Answer

Attribution assigns credit for conversions to specific touchpoints in the customer journey, while incrementality measures the true causal impact of marketing by comparing test and control groups. Attribution can be misleading due to correlation issues, while incrementality provides a more accurate measure of marketing effectiveness.

Question 3

What is a good incrementality lift percentage?

Accepted Answer

A good incrementality lift varies by industry, channel, and campaign objectives. Generally, a relative lift of 10-30% is considered good, while anything above 30% is excellent. However, even a 5% lift can be valuable if it's statistically significant and the campaign has large scale.

Question 4

How do I set up an incrementality test?

Accepted Answer

To set up an incrementality test: 1) Define clear objectives, 2) Create randomized test and control groups, 3) Ensure the only difference between groups is exposure to the marketing activity being tested, 4) Determine appropriate sample sizes for statistical significance, 5) Run the test for a sufficient duration, and 6) Analyze results using this calculator.

Question 5

What sample size do I need for an incrementality test?

Accepted Answer

Sample size depends on your baseline conversion rate and the minimum lift you want to detect. Generally, you need larger samples for lower conversion rates or to detect smaller lifts. For most tests, aim for at least 1,000 users per group, though high-traffic campaigns may require 10,000+ per group for statistical validity.

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