Welcome to Quarter 3: Design & Copy. The infrastructure is solid. The list is clean. Now we focus on the email itself — starting with the most important real estate in your entire email program: the subject line.
This Week’s Lesson
The subject line has one job: get the email opened. Everything else — copy quality, design, CTAs — is irrelevant if the subject line fails.
Length: Subject lines between 40-60 characters (6-10 words) consistently outperform longer ones on most platforms. Mobile inboxes show roughly 30-40 characters. Front-load the most compelling part of your subject line — don't bury it after the 30-character mark.
What works: Specificity ('Reduce email bounce rate by 34%') beats vague promises ('Improve your email performance'). Questions create cognitive engagement ('Are you making this SPF mistake?'). Numbers signal concrete value ('7 subject line formulas that double open rates'). Urgency works when genuine, not manufactured.
What doesn't work: ALL CAPS (spam signal, also aggressive). Excessive exclamation marks!!!! (spam trigger and unprofessional). Misleading subjects that don't match the content (damages trust and raises complaint rates). Overused phrases like 'Don't miss this' and 'Act now.'
Personalization: First-name personalization in subject lines lifts open rates by 10-14% on average — but only when used selectively. Every email starting with '{first_name},' stops being personalization and starts being a template.
A/B test every subject line when volume allows. Most ESPs support native A/B testing on subject lines with a defined winner metric (open rate). Even testing 2 variations per email compounds to a meaningful advantage over a year of sends.