Most teams stop at subject‑line testing. The real wins are in send times, content structure, CTA design, and layout choices.
Why tests fail
Underpowered sample sizes (at least 1,000 per variant) and changing too many variables at once.
Testing send times
Morning vs. afternoon, weekday vs. weekend. B2B often peaks Tuesday–Thursday 9–11 am; B2C performs better on weekends.
Testing content structure
Long‑form vs. short‑form, single‑topic vs. multi‑topic. Plain‑text often beats HTML for B2B.
Testing CTAs
Button color, copy, placement, number, and size. High contrast and action verbs win.
Testing personalization depth
Beyond the first name: purchase history, browsing behavior, location, engagement level. 2–3x better performance.
Test roadmap
Week 1–2: send times. 3–4: subject lines. 5–6: content length. 7–8: CTAs. 9–10: personalization. 11–12: combine winners.
Analyzing results
Track the whole funnel: opens → clicks → conversions → revenue. Always optimize for the metric closest to revenue.
Marcus Rivera
Writer at EngageBay. Passionate about email marketing, automation, and data‑driven growth strategies.