{"id":"mkt2-email-subject-test-pick-metric","audience":"marketing","category":"data","track":"marketing","technique":"verification","level":"advanced","title":"Call an email subject test using clicks, not inflated opens","free":false,"task":"Your team ran a subject line test and wants a decision. Write a prompt for exactly 3 plain-text lines: \"Metric:\" naming the metric to decide on, \"Math:\" showing each variant's click rate as clicks divided by emails sent, and \"Decision:\" naming the winner and one reason under 12 words. The test goal was clicks to the pricing page. No other text, under 70 words.","materialLabel":"Test results (attached to your prompt automatically)","material":"EMAIL TEST - November newsletter subject lines\nGoal set before the test: more clicks to the pricing page.\n\nVariant A: \"Your Q4 plan, simplified\"\n  Sent: 5,000   Opens: 1,400   Clicks to pricing: 100\nVariant B: \"You won't believe what's new\"\n  Sent: 5,000   Opens: 1,750   Clicks to pricing: 85\n\nNotes:\n- Open counts include automatic opens by mail apps that preload images, so opens run high for some audiences.\n- B was sent to the list's first half, A to the second half; the list is sorted by signup date, so B's half has older subscribers.\n- The team lead said: \"B won on opens, ship it.\"\n- Unsubscribes: A 12, B 31.","rules":[{"type":"plainText"},{"type":"maxWords","max":70}],"mistakes":[{"title":"Deciding on opens","why":"The AI goes with the team lead's open-rate win.","fix":"Add: \"Decide on the goal metric, clicks to pricing, not opens.\"","checks":["r0","r2"]},{"title":"Stating rates without working","why":"You can't check a rate with no numbers.","fix":"Say: \"Math line shows clicks / sent for each variant.\"","checks":["r1"]},{"title":"Adding a long analysis","why":"AI adds caveats and next steps.","fix":"Say: \"Exactly three lines, nothing else.\"","checks":["maxWords"]},{"title":"Letting markdown through","why":"AI adds bold text and headings by default.","fix":"Add: \"Plain text only, no bold, no headings.\"","checks":["plainText"]}],"promptHints":[{"label":"Names the three labels","patterns":["metric:.*math:.*decision:","decision:"]},{"label":"Picks the goal metric","patterns":["goal","clicks to (the )?pricing","not opens"]},{"label":"Shows the math","patterns":["clicks (divided by|/|over) (emails )?sent","show the math"]},{"label":"Limits the reason","patterns":["under 12 words","12 words"]},{"label":"Asks for no extra text","patterns":["no other text","only (these )?(three|3)","nothing else"]}],"hint":"Pick the metric from the goal, not from the biggest number. Give the three labels, the formula and the metric to decide on.","mission":"Pick the winning subject line using click rate, not opens.","musts":["Clicks divided by sent","Show each variant's math","Reason under 12 words"],"rubricLabels":["The output has three lines starting with Metric:, Math: and Decision:, and the Metric line names clicks to pricing (the stated goal), not opens","The Math line shows 100/5,000 = 2.0% for A and 85/5,000 = 1.7% for B","The Decision line names A as the winner with a reason under 12 words, and does not call B the winner because of opens"]}