Email vs SMS: What Each Channel Is Actually Good At

"Should we be doing SMS?" is one of the most common questions I hear from DTC brands. Usually it comes with the assumption that SMS is the shiny new thing that'll replace email, or that it's just email but shorter.

It's neither. Having run both email and SMS through Klaviyo, the way I think about it is simple: email is your living room, SMS is a tap on the shoulder. They do different jobs, and the brands that get the most out of them are the ones that stop treating them as the same channel.

What email is great at

Storytelling and depth. Email gives you space. You can show a full product range, tell the story behind a launch, explain how to use something, share UGC and reviews all in one go. If you need someone to understand something, email is the place.

Scale without stress. Sending an email to your whole list doesn't cost much more than sending it to half your list. That makes it the natural home for your regular campaigns and your longer flows.

Being scannable later. People don't always act on an email straight away. They save it, come back to it, search their inbox for your discount code three days later. Email has a longer shelf life.

Visual brand building. Your design, photography, tone of voice. Email lets you show all of it.

What SMS is great at

Speed and attention. A text gets seen. People check their phones constantly, and a message sitting on their lock screen is hard to ignore. That's a superpower, but it's also why you have to respect it.

Time-sensitive moments. Flash sales, restocks of a sold-out product, the last few hours of an offer, early access drops. If timing is the whole point, SMS wins.

High-intent nudges. An abandoned checkout text, sent at the right moment, can be really effective because it's short, direct and lands right where people shop: on their phone.

Feeling personal. A well-written text reads like a message from a person, not a newsletter. That's the tone to aim for.

Where SMS goes wrong

Because SMS is so direct, it's also much easier to annoy people. Every text costs money to send, and every text that feels pointless pushes someone closer to replying STOP. A few things I'd avoid:

• Copying your email into a text. If your SMS reads like an email subject line plus "Shop now," it's not adding anything.
• Sending too often. Your email list might happily take a few campaigns a week. Your SMS list probably won't.
• Ignoring the time of day. Klaviyo has quiet hours settings for a reason. Nobody wants a promo text at 11pm.
• Treating every subscriber the same. Someone who just bought doesn't need the same text as someone who's never ordered.

A quick word on consent (especially in the UK)

SMS consent is stricter than people think. In the UK, marketing texts fall under PECR, which generally means you need clear, specific consent before you send marketing messages, and every message needs an easy way to opt out. Email and SMS consent are separate too: someone subscribing to your emails hasn't agreed to texts.

How I'd use them together

The magic is in combining them, not choosing between them. A few examples of how I like to split the work:

So, should you be doing SMS?

My honest take: if your email flows aren't set up properly yet, start there. Email is cheaper, more flexible, and it's the foundation everything else sits on.

Once your core flows are running and you've got a decent volume of customers, SMS becomes a really strong layer on top, especially for time-sensitive messages and high-intent moments. Start small: add SMS to your abandoned checkout flow and your biggest campaigns, measure what it adds, and grow from there.