Engagement & Fatigue

Engagement

Engagement is how recipients react to your email, measured per campaign:

• Open rate — opens ÷ recipients.
• Click rate — clicks ÷ recipients.
• Unsubscribe rate — unsubscribes ÷ recipients.

Engagement isn’t just a vanity metric — mailbox providers watch it closely. High opens and clicks build sender reputation and improve deliverability; rising unsubscribes and complaints erode it. SendLucid uses engagement to rank your best and worst campaigns and to spot audiences that have gone cold.

Fatigue

Fatigue is what happens when you email too often: opens fall, unsubscribes climb, and revenue per send drops even as total sends rise. You’re working the same list harder for less.

SendLucid flags cadence fatigue risk when either is true:

• you sent more than 10 campaigns in the last 14 days, or
• your average gap between sends is under 1 day.

It also surfaces the timing that works best for your audience — the best day of the week and the best time window (morning, afternoon, or evening) by revenue per send — so you can send less but earn more.

Rule of thumb SendLucid recommends for ecommerce: 2–3 campaigns per week. Past that, watch unsubscribe and complaint rates closely.

The fix for fatigue is rarely “email more.” It’s better timing, tighter segmentation, and letting automated flows carry more of the load.