Evaluate Post-Purchase Recommendation Emails

A retailer proposes sending recommendation emails after a purchase. Decide whether the feature is worth building and how you would test it. Explain the recommended products, timing, business value, and possible harm before selecting a model. ### Constraints & Assumptions The reported discussion emphasized product and business reasoning. It raised retention versus acquisition cost and negative effects such as unsubscribes and spam complaints. Treat lower retention cost as a hypothesis to validate for this business, not a universal fact. ### Clarifying Questions What outcome would justify the email? Which customers are eligible and willing to receive this channel? Are recommendations complementary products, replenishment, or another category? What contact-frequency and timing limits apply? ### What a Strong Answer Covers Compare sending with not sending, estimate incremental value after costs and customer harm, choose a reasonable baseline, and define a randomized experiment with engagement and channel-health guardrails. ### Follow-up Questions How would you distinguish an email-caused purchase from one that would occur anyway? What if open rates rise but unsubscribes also rise? How would recent returns or a poor delivery experience change eligibility?