SpaceCRM / Blog
Email A/B Testing: Email A/B Testing Results: What We Learned from 10,000 Campaigns
Email A/B testing results from 10,000 campaigns. Subject lines, send times, CTAs, and personalisation tactics that actually move the needle.
What 10,000 campaigns taught us about subject lines
Short subject lines (under 5 words) and long subject lines (10+ words) both outperform medium-length ones. The key isn't length — it's specificity. 'Meeting Thursday?' converts better than 'Quick Question About Your Pipeline'.
Questions in subject lines get 15% higher open rates than statements. But the question must be answerable with 'yes' — 'Struggling with deliverability?' works; 'What do you think about email marketing?' doesn't.
Send times that actually matter
Tuesday and Thursday mornings (8-10 AM recipient time zone) still outperform other days. But the bigger factor is consistency — sending at the same time every week trains your audience to expect your emails.
SpaceCRM's AI optimises send times per contact based on their historical engagement. Each prospect gets emailed when they're most likely to open.
The one-CTA rule
Emails with a single CTA get 42% higher click rates than emails with multiple CTAs. Every link you add splits attention and reduces the chance of any single action being taken.
SpaceCRM's A/B testing dashboard shows you which CTAs drive actual conversions — not just clicks. Run 2 variants per campaign and let the winner become the control for the next test.