Digital Marketing Academy · Lesson

Cohort and Funnel Queries

Answer retention questions.

What Is a Cohort?

A cohort is a group of users who share a starting event, usually their signup month. Tracking each cohort over time reveals true retention.

Aggregate metrics hide churn; cohorts expose whether new users actually stick around.

SELECT user_id,
       DATE_TRUNC('month', signup_date) AS cohort_month
FROM users;

The first step is labeling each user with their cohort. DATE_TRUNC rounds signup dates down to the month so users group cleanly.

Store this as a reusable building block for everything that follows.

SELECT DATE_TRUNC('month', signup_date) AS cohort_month,
       COUNT(*) AS cohort_size
FROM users
GROUP BY 1
ORDER BY 1;