Two years of UK e-commerce — 805,549 transactions, £17.7M of revenue (UCI Online Retail II). I scored every customer on Recency, Frequency, Monetary and priced the next quarter's marketing.
Top 5% of customers = 52% of revenue. Add the next 6% and you're at 66%. Add the next 9% and you're at 77%. Champions alone — 609 customers averaging 8 days since their last order — account for £8.8M, or 49.5% of the book.
Below the top 11%, every additional segment matters less than the marginal cost of keeping one Champion happy. The playbook prices their attention the highest.
And the at-risk pile? 188 customers in At Risk + Can't Lose Them. People who were buying and just stopped. £943k of historical revenue, the right moment to intervene.
Rule-based segmentation matching the Klaviyo / Mailchimp / Putler canon. k-means confirms the same Champions cluster — meaning the labels aren't arbitrary.
VIP · Champions, Can't Lose Them · $6-22/customer · ROI 23.8× on Champions alone.
Retain · Loyal, Potential Loyalist, At Risk · $2.50-18/customer.
Reactivate · Hibernating, About to Sleep · $0.80-5/customer.
Don't spend · Lost, Promising. A coupon to a 1-year-stale customer is theatre.
sql/rfm.sql for the SQL-first reviewer.