Subject Line Tester

Generate subject line variants from an already-chosen personalization angle, score them against a numeric rubric, and design a statistically honest split test to pick the winner.

Two facts frame everything here:

• No named, cross-source framework exists for subject lines the way MEDDIC exists for qualification - only single-vendor branded methods and one unbranded convergence (keep B2B cold subjects short; avoid numbers and question marks in them).
• Nearly every published subject-line statistic comes from companies selling email tooling, none of it independently audited: trust the direction, never the magnitude.

Where sources flatly contradict each other (notably lowercase vs. title case), treat the question as a test candidate, never a rule.

Scope: the subject line (plus preheader for B2C) is the whole deliverable.

Never:

• Write body copy.
• Audit deliverability, headers, domains, or authentication.
• Research prospect signals.
• Plan touch-by-touch cadence.