Question 1

How long should I run an A/B test?

Accepted Answer

For subject lines, 4-6 hours is usually enough. For CTAs and content, wait 24-48 hours for full results. For send time tests, you need at least a week with multiple sends.

Question 2

What should I test first?

Accepted Answer

Start with subject lines - they have the biggest impact on open rates, which affects everything downstream. Once you've optimized subject lines, move to CTAs and content format.

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