SMS Newsletter vs. Email Marketing - Which Solution Delivers a Higher ROI?

You're investing in traffic. You're paying for Google Ads, Meta, SEO. Customers land on your site, browse, add items to their cart - and leave. According to the Baymard Institute, which analyzed 50 studies, over 70% of e-commerce carts are abandoned without a completed purchase. So how do you recover that lost revenue - and who is actually receiving your marketing messages?

The answer often comes down to a choice between two channels: email and SMS. Email is the proven, affordable, scalable standard. SMS requires higher per-send investment, but promises significantly greater effectiveness.

In this article, you'll find out which solution delivers a higher return on investment.

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What Do We Mean by "Campaign ROI"?

Before comparing both channels, we need to understand how each one works. Marketing campaign ROI is not open rate or message volume. It's the ratio of revenue generated by a campaign to the costs incurred. In practice, we measure:

• Open rate - what percentage of recipients actually saw the message
• CTR (Click-Through Rate) - what percentage clicked on a link or offer
• Conversion - what percentage of those who clicked made a purchase
• Revenue per campaign - total revenue generated
• Total cost - send cost + contact acquisition cost + operational time

The most common mistake when comparing SMS and email is looking exclusively at send cost. Email is cheapest per send - that's a fact. But what matters is cost per conversion, not cost per message.

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Email Marketing - A Strong Foundation With a Growing Problem

Email is the oldest and still one of the most widely used marketing channels. Its advantages are undeniable: low unit cost, rich visual format, sophisticated automation capabilities, and mature analytics tooling. Most e-commerce platforms have native integrations with email service providers, and every e-commerce business starts building a mailing list from day one.

However, email effectiveness has been declining steadily for years. This isn't just a numbers story - it reflects a fundamental shift in recipient behavior.

Data every email marketer should find concerning:

• Average email open rates in Poland sit at 20–25%, meaning 3 out of 4 messages are never opened.
• Email CTR hovers around 2–3%. Of those who do open, only 1 in 20 clicks through.
• Spam filters are becoming increasingly aggressive. Promotional messages routinely land in "Promotions" or "Spam" folders, especially when brands neglect list hygiene.
• Many people maintain separate email addresses used exclusively for newsletter sign-ups and promotions - accounts opened rarely, irregularly, and without any sense of urgency.
• On mobile devices, email notifications are widely muted. Most users have inbox notifications disabled or check email in scheduled time blocks.

In practice, a list of 50,000 email addresses is not a list of 50,000 active recipients. Once you account for open rates, filters, and real engagement, the number of people actually receiving your message at any given moment is significantly lower - and shrinking every year.

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SMS Marketing - Higher Send Cost, Lower Cost Per Result

Before asking about send costs, ask a different question: how much is a message worth when nearly every recipient reads it?

SMS is more expensive per message than email. But it operates on a fundamentally different effectiveness profile - and that difference is what determines ROI.

Numbers that reframe the conversation:

• SMS open rates are approximately 97–98%. Text messages are read almost universally - because they arrive in the same place as messages from family and friends.
• Average time to read an SMS is 3 minutes from delivery. No other marketing channel offers that level of immediacy.
• SMS CTR is 6–8× higher than email.
• No spam folder. No algorithm. The message either reaches the recipient or it doesn't - no filter decides who gets through.

There's another dimension rarely captured in simple cost comparisons: the context of delivery. An SMS arrives in the same place as messages from people who matter. It's not a Promotions folder you scroll through over morning coffee. It's a notification that appears on a locked screen at any hour of the day - and triggers an immediate response.

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Where Email Wins - An Honest Assessment

A rigorous analysis requires acknowledging that email remains the channel of choice in certain contexts. A few cases where email wins outright or holds its own:

• Long-form educational content and editorial newsletters. Email supports rich formatting: images, GIFs, multi-section layouts, long-form copy. SMS is inherently brief.
• B2B nurturing and extended purchase cycles. In decision-making processes that unfold over weeks or months, email builds relationships and delivers consistent value without feeling intrusive.
• Historically engaged segments. If you have a subscriber segment with 45%+ open rates, email is both effective and economically sound.
• Transactional messages and confirmations. Order confirmations, invoices, shipping details - these are a natural fit for email, not SMS.

SMS and email serve different functions in the sales funnel. Brands achieving the highest results use both - but deploy each for the job it was built to do.

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Why a Phone Number Is Harder to Earn - and Why That's an Advantage

Here's an argument frequently overlooked in ROI discussions: list quality isn't just about contact volume - it's primarily about the intent behind each entry.

Entering an email address is reflexive. Most internet users have trained themselves to provide an email at every sign-up, purchase, or content download. Some of those addresses are throwaway inboxes - accounts created purely for promotional sign-ups that are rarely, if ever, checked.

Providing a phone number is an entirely different decision. A phone number is personal. We give it to family, friends, doctors, and employers - not to every brand we encounter. When a customer leaves their phone number, it signals a genuine desire to stay in contact. That's not a casual sign-up - it's an act of intent.

Double Opt-In as a Quality Filter

In professional SMS marketing platforms such as 2way, the sign-up process runs through a Double Opt-In mechanism: the user enters their number, receives a one-time verification code via SMS, and only enters the database after confirming it. This eliminates fake numbers, typos, and low-intent sign-ups.

A list of 2,000 phone numbers built through Double Opt-In can be realistically more valuable than a list of 20,000 email addresses where half are inactive or invalid. Smaller list, higher conversion, higher ROI per contact.

This fundamentally changes how you should think about building an owned audience. List size matters - but quality and intent matter more.

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Scenarios Where SMS Delivers the Highest ROI

Theory is one thing. Here are the specific situations where SMS generates the best return on investment.

Scenario 1: Abandoned Cart With a Discount Code

 A customer visits your site, adds products to their cart, enters a discount code - and doesn't complete the purchase. In the traditional model, that sale is lost. Through 2way's e-commerce integration, it's possible to detect that moment and trigger an automated SMS:

"Hey, your cart at [BRAND] is still waiting. Your coupon is still active."

Sent 4–24 hours after abandonment, it arrives at exactly the right moment: the purchase intent is still fresh, and the code creates urgency. This is one of the highest-converting scenarios in e-commerce.

Scenario 2: Reminder About an Unused Discount Code 

A customer signed up, received a 20%-off code - and nothing happened. No visit, no redemption. In 2way, this is visible in real time - every code is tracked individually. You can configure automated reminder sequences: the first after 7 days, the second after 21 days. People who have already taken the first step (signing up) are significantly closer to a purchase decision. The cost of reaching them is minimal; the conversion potential is high.

Scenario 3: Post-Season Customer Reactivation 

A customer bought once, during the summer season, then disappeared. Six months have passed. A new season is approaching. Rather than burning budget on ads targeting cold audiences, the brand sends its existing database a personalized re-engagement SMS. The message reaches people who already know the brand, have purchased before, and - critically - left their phone number.

Scenario 4: Offline Sign-Up → SMS → Online Purchase 

This scenario is unique to tools that bridge the offline and online worlds. NFC stickers and QR codes with individual identifiers, placed in physical retail locations, allow brands to collect phone numbers from customers who visit in person. In high-traffic locations, these solutions generate an average of 30 sign-ups per day from a single point of capture.

That contact - acquired in-store - becomes the entry point for online communication. The customer receives an SMS with a code for the e-shop. The brand gains an omnichannel customer who buys both offline and online. This is an asset no advertising campaign can build as efficiently.

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How to Start Building an SMS List Without Overhauling Your Systems

One of the most common objections to SMS marketing implementation is the assumption that it requires a lengthy, expensive technical project. In practice, it doesn't.

Tools like 2way come with a ready set of subscriber acquisition mechanisms that can be deployed quickly:

• Pop-up and teaser on your website with a sign-up form and automated Double Opt-In.
• Landing page - a ready-to-use sign-up page that requires no IT involvement, hosted directly on the platform's servers.
• NFC stickers and QR codes - for physical retail, events, print materials, and out-of-home advertising, each with a unique identifier for performance tracking.

Integration with your CRM and e-commerce platform works bidirectionally: 2way pushes data on new sign-ups, clicks, and redeemed codes into your system, while simultaneously pulling CRM data to prevent list duplication. A dedicated account manager handles configuration and supports your first campaigns.

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SMS vs. Email - Who Wins on ROI?

SMS wins ROI in sales campaigns - cart recovery, customer reactivation, and conversion-oriented communications. The higher send cost is offset by a multifold advantage in open rate, CTR, and final conversion. In absolute terms, a well-configured SMS campaign to a quality list generates higher revenue than a comparable email campaign, despite higher operational costs.

Email remains a valuable channel for content-driven communication, nurturing, longer purchase cycles, and historically engaged segments. It's a relationship-building tool - not a channel for closing sales in minutes.

There's one more argument that goes beyond a simple ROI comparison: an SMS list is an owned asset. It belongs to the brand. No algorithm decides whether a message reaches its recipient. No platform changes the rules overnight. A brand that builds a database of phone numbers builds an independent communication channel - resilient to social media shifts, rising CPCs on Google, or tightening spam filters.

In a world of rising customer acquisition costs and declining paid traffic performance, owning a verified, permission-based contact list is one of the most important investment decisions an e-commerce brand can make.

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