The false choice
Every growth review asks: WhatsApp or email? The answer is both, doing different jobs. WhatsApp wins speed and urgency - 98% open rates, three-minute response windows. Email wins volume and storytelling - long-form, low-cost, scalable. The profit is in the sequence, not the pick.
The division of labor that works
Cart abandonment: WhatsApp first - a single urgent message within the hour - email follows at 24 hours for the non-openers. Win-back: email builds the story (new arrivals, account summary), WhatsApp delivers the trigger (a credit expiring, a restock alert). Reorders: WhatsApp's low-friction 'order again' beats email's click-to-checkout by a wide margin. Broadcasts and campaigns: email carries volume, WhatsApp carries the VIP segment.
The combined funnel
A shared opt-in at checkout gives you both surfaces from one action. Each channel feeds the other: WhatsApp subscribers get email-only offers; email subscribers get WhatsApp-only urgency windows. The brands running this combination see 18-25% of monthly sales from lifecycle channels - with WhatsApp contributing a third of that on a fraction of the list size.
The rule: treat them as one conversation across two surfaces. Customers do not care which channel you call it - they care that the right message arrives at the right speed.
