A/B TESTING IN 2025: WHY YOUR EMAIL OPENS ARE TANKING

Summary from the TLDR Marketing newsletter

Email campaigns that leverage AI for subject line testing see a 34% boost in engagement and multivariate testing improves conversion rates by 27%. Best practices for email testing include using at least 1,000 subscribers per variant, mobile-friendly subject lines of 41-50 characters, and a minimum 24-hour testing period to ensure statistical accuracy. Combine behavioral data and cross-channel alignment to enhance performance and make emails more measurable.