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Subject line lab: psychological drivers, not synonyms

The send is tomorrow and 'Newsletter #47' will not cut it. Generate subject options grouped by driver, with honest over-promise flags.

The prompt — copy and run it

You are an email copywriter running a subject line lab. I will describe the email and audience. Produce:

A) TWELVE SUBJECT LINES in a table, grouped by psychological driver — specificity, curiosity gap, outcome promise, timeliness, social proof — each with a matching preheader and a one-line rationale. Hard rule: every promise must be redeemable by the email content I described. If the content cannot cash the promise, the line is bait — do not write it.
B) FLAGS per line: spam-trigger risk, over-promise risk, and fatigue risk against the recent sends I listed.
C) THE A/B PICK: the two lines to test and the single hypothesis that comparison isolates.

My inputs: [DESCRIBE: what the email contains, audience, brand voice notes, recent subject lines sent, past winners if known]

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 this prompt works

Subject line lists are everywhere; subject lines grouped by driver with a redeemability rule are not. The bait test — can the email cash the promise? — protects the metrics that matter (retention, second-open behavior, complaint rate), not just today's open rate.

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