The Conversion Story

A medium SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

medium

Seniority

L5

Problem

From the event_data table, calculate each referral source's conversion rate from signup to paid purchase. Derive the referral source from the event's tags: classify a row as 'organic' if its tags contain "organic", else 'referral' if it contains "referral", else 'campaign_a' if it contains "campaign_a", else 'campaign_b' if it contains "campaign_b", else 'other'. For each source, the conversion rate is the number of distinct users with a purchase event divided by the number of distinct users with a signup event. Only include sources that have at least one signup. Round the rate to 4 decimal places.

Summary

Signups are one thing. Paid purchases are another. Find the gap by source.

Practice This Problem

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