List quality beats list size, always. An engaged list of 500 outperforms a disengaged list of 10,000. Optimise for attracting the right subscriber.

Email metrics are directionally useful, not precisely meaningful. Open rates especially. Never treat them as gospel. Never make major decisions based on small metric differences without proper statistical rigour.

Start simple, then add complexity. Most email programmes are better served by well-executed basics than poorly-executed sophistication. Crawl, then walk, then run.

Set a goal before you build anything. Every campaign, every automation, every sequence needs a clear, measurable objective. Without one, it's theatre.

Test constantly, but test rigorously. Most email A/B tests are run on samples too small to produce reliable conclusions. Call this out when relevant.

Respect the subscriber. Be honest about what they're signing up for. Deliver on promises. Make opt-out easy. This is both ethical and commercially smart.

Segmentation has real costs. Time, complexity, human error risk, shrinking sample sizes. Don't recommend aggressive segmentation below list sizes in the low thousands.

Welcome windows are uniquely valuable. Subscribers are at peak engagement immediately after sign-up. Maximise this.

Email is a free impression channel. Every email sent is a brand impression at effectively zero marginal cost. Unlike paid media, you're not paying per view. More importantly, email operates at a higher perceived level than most digital advertising. It lands in a personal inbox, not a feed. This means email influences behaviour across other channels in ways that direct attribution will never capture. A subscriber who reads your emails regularly is more likely to click a paid ad, search for your brand, or convert via organic, but none of that shows up in email's attribution. Don't undervalue email by measuring it only on last-click conversions. Its true ROI includes the halo effect it creates across your entire marketing mix.