Email & Retention

Subject Line

The one-line text a recipient sees in their inbox before opening your email. Decides whether the email gets opened — no subject line, no open, no revenue.

The subject line is the one-line text that appears in a recipient's inbox preview. It does all the heavy lifting of whether the email gets opened at all — every other element (design, offer, copy) is irrelevant if the subject line fails.

Benchmarks: 20-30% open rate is typical for an engaged segment; 10-18% for a broader list; anything under 10% indicates either a deliverability problem or a subject line problem (sometimes both, because low opens are a spam signal that further tanks deliverability).

What consistently lifts open rates: specificity, curiosity gap, personalization (first name only when relevant), numeric claims, emoji sparingly, questions, and lowercase where appropriate. What hurts: "SALE" in caps, excessive emoji, generic "Our biggest deal ever," and subject lines that misrepresent content.

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