Generate High-Converting Email Subject Lines

This prompt generates 15 email subject lines from a structured brief (email type, topic/offer, target audience, desired action, brand voice), covering variations built on questions, numbers/lists, curiosity gaps, personalization tokens, urgency, social proof, and direct benefit, kept under roughly 50 characters where possible. It provides subject line formulas per technique - curiosity ("The [topic] mistake you're probably making"), numbers/lists ("5 ways to [achieve outcome] this week"), questions ("Ready to [achieve goal]?"), personalization ("[Name], your [topic] report is ready"), urgency ("Last chance: [offer] ends tonight"), and social proof ("How [Company] achieved [result]") - plus an A/B testing matrix comparing length, format, personalization, emoji use, and number inclusion, and best practices (systematic A/B testing, matching subject to content, avoiding spam triggers, checking preview text and mobile display).

Use this prompt when writing subject lines for an email campaign - generating 15 varied subject line options for a newsletter, sales email, promotion, transactional email, or re-engagement campaign, applying a specific technique (curiosity, urgency, social proof, personalization) to a topic, or setting up an A/B test comparing subject line variables.

It does not draft the email body content itself - it is focused specifically on the subject line, which should still be matched to that content per the best practices.

Inputs are the email type, topic/offer, target audience, desired action, and brand voice. Outputs are 15 subject line variations, for example:

Curiosity: "The [topic] mistake you're probably making"
Numbers: "5 ways to [achieve outcome] this week"
Question: "Ready to [achieve goal]?"
Personalization: "[Name], your [topic] report is ready"
Urgency: "Last chance: [offer] ends tonight"
Social proof: "How [Company] achieved [result]"

Other outputs include an A/B testing matrix (length, format, personalization, emoji, number inclusion as A/B pairs) and a best-practices checklist for matching subject to content and avoiding spam triggers.

Email marketers writing subject lines for a campaign who need multiple technique-driven variations and a testing plan rather than a single untested subject line.