The single biggest lever in email is still the welcome flow. It's the only moment a subscriber has actively raised their hand, and most brands waste it with a 15% off code and silence for two weeks.
Our default welcome series is five emails over ten days: story, product, proof, objection, offer. Open rates on that sequence run 45–60% for our clients, and it accounts for a disproportionate share of first-time revenue.
For the ongoing newsletter, cadence matters less than voice. One good email every two weeks beats a mediocre weekly send every time.