{"id":"dat-mkt-cpa-after-refunds","audience":"marketing","category":"decisions","technique":"context","title":"Compare ad channels on cost per kept customer","free":false,"task":"You're deciding where to move next month's ad budget. Your team judges channels on cost per kept customer: spend ÷ (conversions − refunded), not raw conversions. Write exactly 3 numbered lines, one per channel, each showing that math, then one unnumbered sentence saying which channel to move budget from and to. Plain text, under 70 words.","materialLabel":"October channel report (attached to your prompt automatically)","material":"OCTOBER PAID CHANNELS - Lumen Candle Co.\n\nChannel | Spend | Conversions | Refunded\nSearch | $6,000 | 210 | 10\nSocial | $4,500 | 200 | 80\nInfluencer | $2,800 | 110 | 10\n\nNotes:\n- Social had a 40%-off code that leaked to a coupon site. Lots of those orders were returned.\n- The ads agency's recap calls Social \"our most efficient channel at $22.50 per conversion.\"\n- Influencer was two creators; one wants to renew for November.\n- Search costs went up after the holiday rush started.\n- Budget for November is the same total: $13,300.\n- Refunded orders were returned within 30 days for a full refund.\n- Conversions are first purchases from new customers.\n- Search is mostly brand and gift keywords.\n- CMO wants a short recommendation before the November budget locks.","rules":[{"type":"numberedItems","count":3},{"type":"plainText"},{"type":"maxWords","max":70}],"mistakes":[{"title":"Not defining the metric","why":"The AI uses raw conversions and agrees with the agency that Social is best.","fix":"Add: \"Cost per kept customer = spend ÷ (conversions − refunded).\"","checks":["r0","r2"]},{"title":"Not showing the math","why":"Bare costs hide whether refunds were taken out.","fix":"Add a line to copy: \"1. Search: $6,000 ÷ (210 − 10) = $30\"","checks":["r1","numberedItems"]},{"title":"Leaving the ending open","why":"The AI writes a long strategy section.","fix":"Add: \"Then one sentence: move budget from X to Y.\"","checks":["r2"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting. Ask for a total word limit and it often lands over it.","fix":"Cap each part: \"each line under 12 words, the sentence under 15.\"","checks":["maxWords"]},{"title":"Forgetting where it goes","why":"AI loves markdown tables and bold, which show up as clutter in a budget doc comment.","fix":"Add: \"Plain text, no bold, headings or tables.\"","checks":["plainText"]}],"promptHints":[{"label":"Defines the metric","patterns":["kept","refund","minus|−|-"]},{"label":"Asks to show the math","patterns":["show (the |your )?(math|work)","x \\$|\\bx\\b.{0,10}=","calculation","step"]},{"label":"Asks for a move","patterns":["move.{0,20}(budget|from)","from .{1,20} to"]},{"label":"Sets a word limit","patterns":["\\d+\\s*words","word (limit|count)","under \\d+"]},{"label":"Asks for plain text","patterns":["plain","no bold","no markdown","no formatting","no (headings|tables)"]}],"hint":"The agency's number ignores refunds. Tell the AI how your team measures, and ask it to show each channel's math before it recommends.","rubricLabels":["Social is $4,500 ÷ (200 − 80) = $37.50 per kept customer, not the agency's $22.50","Search is $6,000 ÷ 200 = $30 and Influencer is $2,800 ÷ 100 = $28","The final sentence moves budget from Social to Influencer, after the three lines, with no intro"]}