Email vs SMS vs WhatsApp automation in Croatia: when to use which

The biggest mistake in marketing automation isn't "which tool", it's "which channel for which trigger". Appointment reminder by email = 40% no-show. Same reminder over WhatsApp = 8%. The number doesn't change, the channel does.

Real HR market data

| Channel | Open rate | Click/reply | Cost/msg | |---------|-----------|-------------|----------| | Email | 22–35% | 2–4% | ~€0.001 | | SMS | 85–95% | 8–12% | €0.04–0.06 | | WhatsApp Utility | 92–98% | 15–30% | €0.02–0.04 | | WhatsApp Marketing | 88–95% | 20–35% | €0.08–0.15 | | Viber Business | 85–92% | 10–20% | €0.03–0.05 |

Decision table — which channel per trigger

• Appointment reminder (24h before) → WhatsApp Utility (fallback SMS)
• Payment / invoice confirmation → Email + WhatsApp
• Post-service follow-up / NPS → WhatsApp Service (free within 24h)
• Newsletter / education → Email (best long-term ROI)
• Flash promo / restock → WhatsApp Marketing + Email
• Missed-call re-engagement → WhatsApp Service or SMS
• Reactivation after 6 months silence → Email (cheap) → if clicked → WhatsApp
• Onboarding sequence (7–14 days) → Email + 1–2 WhatsApp touchpoints

HR rules: GDPR + Meta

1. Explicit consent per channel. Email consent ≠ SMS or WhatsApp consent.
2. WhatsApp opt-in must be double — signup checkbox + "YES" reply to first message.
3. Opt-out in every marketing message (STOP for SMS/WhatsApp, unsubscribe link for email).
4. Marketing-category WhatsApp only from Meta-approved templates.

Frequency that doesn't burn out the audience

• Email: 1–4 newsletters/month + event-based
• SMS: max 2–3 marketing/month
• WhatsApp: max 1 marketing message per week per contact

Exceeding = spam reports, number ban, inbox reputation loss.

Recommended stack

For a Croatian business under 50k contacts, one tool covers all three channels cheapest — the [WhatsApp marketing guide](/resources/whatsapp-marketing-hrvatska-2026) and [marketing automation for small businesses](/resources/marketing-automatizacija-mala-poduzeca-hrvatska) go deeper into implementation.

Our [automation service](/services/automation) sets up all three channels, templates and rules in one package.