PromptSharp › Daily briefs › September 15, 2026
PromptSharp Daily · free web issue · #101Prompt of the day
September 15, 2026 · the free cross-vertical sampler: get better at AI and prompting, and see the sharpest prompts from across the network. Today's comes from Marketing.
Channel plan red-team: find the failure before the spend does
The channel plan is drafted and everyone likes it — which is exactly when it should be red-teamed. Run the adversarial pass before the money moves.
You are a skeptical marketing consultant hired to find the flaws in a campaign plan before launch. I will paste the plan. Produce: A) FAILURE MODES ranked by expected cost, each tied to a specific line of my plan with its evidence status (shown in my inputs vs hypothesis): audience-channel mismatch, budget too thin to clear an effective frequency on a channel, overlapping audiences paying twice for the same person, measurement gaps that will make results unreadable after the fact, and creative-format mismatch with placement. B) The THREE plan changes with the best cost-to-risk-reduction trade, argued from my numbers. C) A PRE-LAUNCH CHECKLIST: tracking verified end-to-end, naming conventions, holdout or baseline agreed, and budget-pacing alerts phrased as decision rules. My plan: [PASTE: channels, budget split, flighting, audiences per channel, objective, creative formats, measurement setup] Rules: Do not invent, estimate, or fabricate any statistic, benchmark, or performance figure — if a number is not in the material I give you, write "not provided" and flag it. Mark every claim I should verify in my analytics or source systems before it is published or presented. Never include customer personally identifiable information or client-confidential terms.
Why it works — Plans fail on things nobody wrote down: too little weight to matter on a channel, two line items buying the same user, a KPI that will be unreadable post-launch. A ranked failure-mode read costs one prompt; discovering the same list in week three costs the quarter.
Use AI today — a workflow to steal
Catch AI's mistakes by asking what it assumed
Confident-but-wrong is the #1 AI risk at work. Surfacing its hidden assumptions is a 10-second insurance policy on every important output.
After any answer you'll act on, ask: 'What did you assume that I didn't tell you? What would change your answer if it were wrong?'
- Get the answer.
- Ask for its assumptions + what would flip them.
- Verify the load-bearing ones.
Sharpen it: Use AI to think, not just to type. 'Poke holes in this,' 'what am I missing,' 'argue the other side' — it's a free thought partner, which is often worth more than the draft.
Elsewhere in the network today
Two professional briefs and one personal brief, plus one for students, rotating daily — every one of them free to read right now.
Product Management
Today in Product Management: PRD one-pager: from a problem statement to a spec engineers can build
Dev & Engineering
Today in Dev & Engineering: Design doc skeleton with the alternatives you'll actually be asked about
Focus & Productivity
Today in Focus & Productivity: The overwhelm reset: cut a bloated list down to what today can actually hold
Students
Today in Students: Pressure-test YOUR thesis and outline (before you write the draft)
What changed in AI today
The Bad Guy With An AI Named Claude
Re-run your single most-repeated task on the newest model. Capability jumps quietly reset what's worth automating — the work that was 'too messy for AI' six months ago is often trivial now. Re-test,…
Big Brother logs in to ChatGPT
Read this as a signal, not a to-do. The operators who stay current — scanning 5 minutes a day — compound a real edge over peers who tune AI out until it's forced on them. File it, watch the trend,…
Generative AI can help fix market research. Here’s how
Pressure-test your planning assumptions against this. Even if it's not your job to trade on it, leaders who track the AI/macro picture make better hiring, budget, and timing calls than peers who…
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