SMS, email or WhatsApp: which channel works best for requesting reviews
SMS: the most direct, the most expensive
SMS has the highest open rate of the three (usually read within minutes) and works very well for physical businesses with one-off visits — restaurants, salons, repair shops. It's the most expensive channel per send, so it's usually reserved for right after the experience, not repeated reminders.
Email: the cheapest, the most ignored
Email is practically free to send at volume, but it competes against a crowded inbox — its real open rate tends to be noticeably lower than SMS or WhatsApp. It works best when there's already an email relationship with the customer (booking confirmations, invoices) and the request piggybacks on that existing thread.
WhatsApp: the balance, if the business already uses it
When a business already talks to customers over WhatsApp (bookings, confirmations), asking for the review on the same channel feels natural and gets very high response rates. Cost per message sits between SMS and email. The main barrier isn't price, it's initial setup: it requires a verified WhatsApp Business account and message templates approved by Meta.
The practical recommendation
There's no universal "winning" channel — it depends on where your business already talks to its customers. The most effective strategy combines all three: WhatsApp or SMS for the moment right after the experience, and email as a safety net for contacts with no phone number on file.