Both channels genuinely work, and the real question is not which is universally "better" but which works better for your specific customer relationship — and whether combining them is worth the modest extra effort. The honest answer for most businesses is that you should not have to choose at all: the two channels have complementary strengths, and the highest-performing review systems use them together in a deliberate sequence rather than betting everything on one. Still, it helps to understand exactly what each does well, because that tells you which to lead with and which to hold in reserve as the follow-up.
SMS: higher open rates, faster action
Text messages have open rates above 90%, compared to around 20-30% for email. Most texts are read within 3 minutes of delivery. For a review request, that means a customer sees your message while the experience is still fresh — which is exactly when they are most likely to act. The downside is that SMS feels intrusive to some customers if you do not have an established relationship, and some industries have stricter compliance requirements around text messages.
Email: more control, works for complex messages
Email allows more context and formatting. You can include the customer's name, reference their specific service, and give clearer instructions with a button. Email also reaches customers who prefer not to share their phone number. Response rates are lower than SMS, but email review requests still outperform no follow-up at all by a wide margin.
The combination approach
The highest-performing review collection systems do not pick a side — they send an email first and then a short SMS follow-up three to five days later for anyone who has not yet responded. The email sets context and does the explaining; the text, arriving later, is the nudge that actually converts the people who meant to and forgot. Customers who respond to the first email never receive the text, so no one feels double-asked or pestered. This staggered, two-channel approach captures both the fast responders who act on the first message and the larger group who simply needed a second, lighter touch a few days on — which is exactly why it consistently beats either channel used alone.
Which to start with
If you already have customer phone numbers on file and consent to text them, start with SMS — the faster results are motivating while you are building the habit, the messages are simpler to write, and the higher open rate gives you an early win to build on. If you mostly have email addresses, start there instead rather than forcing customers onto a channel you do not have permission for. Either way, treat your first channel as the foundation and add the second once the first is running smoothly; trying to launch both at once usually means neither gets set up well. Start with whichever channel you already have the details and consent for, prove the process works, then layer in the other for the follow-up.
Cost and deliverability trade-offs
There is a practical difference beyond open rates. Email is essentially free to send at any volume, which makes it ideal for large customer lists and for businesses on tight margins. SMS carries a small per-message cost and tighter regulatory requirements, but it buys you the dramatically higher open rate. For most businesses the math favors using SMS for the moments that matter most (the immediate post-service ask) and email for breadth and follow-up. Watch your SMS volume if you are cost-sensitive — but remember that a single new customer won from a review usually pays for thousands of texts.
Matching channel to your customer relationship
The right channel also depends on how your customers already interact with you. A med spa or salon that texts appointment reminders has an established SMS relationship, so a review text feels natural. A B2B service that communicates entirely over email should lead with email. A retail shop that only has email addresses from loyalty signups uses email by default. Meet customers on the channel they already associate with your business — a review request that arrives the same way your other communication does feels expected rather than intrusive.
The sequence that captures the most reviews
The highest-converting setup is not "SMS or email" — it is a timed sequence. Send the first request on the channel most likely to be seen quickly after service (usually SMS for in-person businesses, email for online ones). Then, for anyone who has not responded, send one follow-up on the other channel a few days later. Using two channels staggered over several days reaches both the instant responders and the people who needed a different nudge — and consistently outperforms relying on either channel alone.
Compliance note: Always get explicit consent before sending marketing SMS messages. Use an opt-in at the point of service or purchase, and include an opt-out. SnappyRatings handles both channels and opt-outs automatically. Run email and SMS review requests together →