For decades, SMS was the go-to tool for direct customer communication. It had immediate reach, high open rates, and worked on every phone.
Then WhatsApp arrived and changed the game.
Now e-commerce brands are faced with a decision: stick with SMS, switch to WhatsApp, or run both channels?
On the surface, the answer seems clear—WhatsApp is superior. But SMS still has advantages that make it valuable for certain use cases. The real answer depends on your audience, budget, and communication goals.
This guide breaks down the reality.
Open Rates: - WhatsApp: 95%+ - SMS: 98%+ (technically higher, but less actionable)
Click-Through Rates: - WhatsApp: 30-50% - SMS: 2-3%
Engagement Rate: - WhatsApp: 30-40% (users reply/interact) - SMS: 5-10% (mostly just delete)
Cost Per Message: - WhatsApp: $0.004-0.02 per message - SMS: $0.01-0.05 per message
Response Time: - WhatsApp: 2-5 minutes - SMS: 24-48 hours
While SMS has a marginally higher open rate, it’s almost misleading. SMS messages are opened because they’re notifications—not because customers are engaged. WhatsApp’s open rate correlates with actual engagement and action.
Every phone on the planet can receive SMS. You don’t need a smartphone, an internet connection, or WhatsApp installed. This matters for certain demographics:
If your customer base skews older or you operate in certain international markets, SMS reach is simply better.
SMS regulations are mature and well-established. TCPA in the US, regulations in EU, and frameworks in virtually every country define SMS marketing clearly.
WhatsApp regulations are still evolving. Different countries treat WhatsApp marketing differently. In some regions, it’s fully compliant. In others, the legal status is ambiguous.
For brands operating internationally or in highly regulated industries, SMS is the safer choice.
Customers expect SMS for critical notifications: - Two-factor authentication - Bank alerts - Appointment reminders - Delivery notifications
For transactional messages, SMS carries authority. People trust SMS in a way they don’t yet fully trust WhatsApp for official communications.
While WhatsApp has higher engagement, SMS’s near-universal open rate means your message will absolutely be seen. There’s no debate, no algorithm, no app interference.
For critical business communications (payment reminders, account alerts), this certainty matters.
SMS is one-way broadcasting. WhatsApp enables conversation. Customers can reply, ask questions, and you can respond in real time.
This fundamental difference makes WhatsApp better for: - Customer support - Order clarifications - Personalized recommendations - Loyalty program interactions
WhatsApp supports images, videos, documents, and interactive buttons. SMS is text-only.
For visual products (fashion, home goods, furniture), WhatsApp’s rich media capabilities are transformative.
WhatsApp costs $0.004-0.02 per message. SMS costs $0.01-0.05. If you’re sending millions of messages, WhatsApp’s cost advantage is substantial.
WhatsApp’s 30-40% engagement rate means customers are actually interacting with your messages. SMS’s 2-3% CTR means most messages are ignored.
For revenue-generating campaigns, WhatsApp converts better.
Critical Transactional Messages: - Two-factor authentication - Payment confirmations - Appointment reminders - Account alerts - Password resets - Delivery notifications
Audiences with Limited Connectivity: - Older customers using basic phones - International markets with low smartphone penetration - Customers in areas with poor data connectivity
Regulatory Compliance: - Industries with strict SMS regulations - International operations requiring maximum legal clarity - Customers expecting SMS for sensitive information
Reach Requirements: - When you need to reach customers regardless of app installation - Backup communication channel - Universal notification requirement
High-Intent Marketing Campaigns: - Abandoned cart recovery - Flash sales and limited-time offers - Back-in-stock alerts - Loyalty program engagement - VIP customer notifications
Customer Service: - Real-time support conversations - Order clarifications - Complaint resolution - Personalized assistance
Visual Product Communication: - Product recommendations with images - Before/after demonstrations - Video tutorials - Catalog browsing
Engagement-Driven Campaigns: - Where you want customers to interact, not just read - Feedback collection - Surveys and polls - Interactive offers
Cost-Sensitive High-Volume: - Sending millions of messages - Large customer base requiring constant communication - Budget-conscious marketing teams
Like email and WhatsApp, SMS and WhatsApp serve different purposes. Winning brands use both:
Build Your SMS List for Transactional Needs: Use SMS for critical notifications where certainty of delivery is paramount.
Build Your WhatsApp List for Engagement: Use WhatsApp where you want to drive action and conversation.
Segment Your Audience: Not all customers should receive both. Some may opt into only SMS. Others only WhatsApp. Some both.
Use SMS as Backup: If WhatsApp delivery fails, SMS serves as a backup channel for critical messages.
Combine for Maximum Impact: Send a WhatsApp reminder with product images, follow up with SMS for time-sensitive urgency.
Let’s compare total cost for a 100,000-person campaign:
SMS Campaign: - Cost per message: $0.03 (mid-range) - Total cost: $3,000 - Open rate: 98% = 98,000 opens - CTR: 2.5% = 2,450 clicks - Conversion: 0.5% = 50 sales - Cost per sale: $60
WhatsApp Campaign: - Cost per message: $0.01 (mid-range) - Total cost: $1,000 - Open rate: 95% = 95,000 opens - CTR: 35% = 33,250 clicks - Conversion: 5% = 1,662 sales - Cost per sale: $0.60
WhatsApp’s cost per acquisition is dramatically lower due to superior engagement and conversion.
But if your SMS audience has better reach (older demographics, international), the comparison changes.
Choose SMS if: - Your audience is older or less tech-savvy - You need maximum regulatory certainty - You’re sending transactional alerts - Universal phone penetration is critical - You operate in highly regulated industries
Choose WhatsApp if: - Your audience is digitally native (mobile-first) - You need two-way engagement - You want to include rich media - You’re sending high-volume marketing campaigns - You need lower cost per acquisition
Choose Both if: - You have diverse customer demographics - You’re sending critical messages that need backup channels - You want to maximize reach AND engagement - You can manage multiple communication channels
WhatsApp is winning because engagement drives revenue. SMS’s open rate advantage doesn’t matter if messages get deleted unread.
But SMS won’t disappear. It’s still the standard for transactional messages and will remain important for audiences SMS reaches better.
The winning strategy for 2024 and beyond: build on WhatsApp first for marketing, maintain SMS for transactional reliability.