The Scenario
An online fashion retailer is launching a new summer collection. The email team wants to optimise not just the subject line, but the entire email — preview text, hero image, CTA button copy, and send time. They have a list of 120,000 subscribers.
The Brief
Design a multivariate testing plan that goes beyond simple A/B. Decide which variables to test simultaneously vs sequentially, calculate the traffic allocation, and define the success criteria.
Deliverables
- A testing matrix showing which variables you are testing and which combinations you are comparing
- The traffic allocation plan: how many subscribers per cell, and why
- The testing sequence: what you test first, second, third (and why you cannot test everything at once)
- The decision framework: how you pick the winner when results are mixed (e.g., higher open rate but lower click rate)
Submission Guidance
A full factorial design with 4 variables × 2 variants = 16 cells. With 120K subscribers, each cell gets 7,500 — is that enough? Show your reasoning.
Submit Your Work
Your submission is graded against the rubric on the right. If you pass, you get a public Badge URL you can share on LinkedIn. There is no draft save, so work offline first and paste your finished response here.