Skip to content
Sellarix

When to Add Email and SMS (Klaviyo vs Mailchimp vs Omnisend)

There's a moment in every store's life where you realize you've been renting your customers. You pay for the click, the visitor buys once, and then...

The Sellarix team · 4 May 2026 · 5 min read

There's a moment in every store's life where you realize you've been renting your customers. You pay for the click, the visitor buys once, and then they vanish back into the algorithm. Next month you pay for them again. That treadmill is exactly what owned-audience marketing, email and SMS, is supposed to get you off of. The question isn't whether you should do it. It's when, and with what. I've set this up for stores doing $8k a month and for brands clearing seven figures, and the honest answer changes a lot depending on where you are. So let me walk through it the way I'd explain it to a founder over coffee, not the way a vendor landing page would.

Why owned channels matter (and the number everyone quotes)

Email keeps getting cited at around $36 back for every $1 spent. That figure traces to Litmus research, and yes, it's an average across a lot of industries, so treat it as directional, not a promise.[1] Retail and ecommerce specifically tend to land higher, with some sources putting it near $45 per $1.[2] SMS is the newer, punchier sibling. Omnisend's benchmark data pegs SMS click-through rates between 21% and 35% versus roughly 3% for email, with SMS ROI ranging from about $21 to $41 per dollar.[3] Label those as benchmarks, not guarantees, because your list quality decides everything. The reason these numbers are so high is boring and powerful. You already paid to acquire the person. Emailing them again is nearly free. The math only works once you have a list worth mailing, though, which is the real gating question.

My honest take on the when

Here's the rule of thumb I actually use. If you're below roughly $5k–$10k in monthly revenue, you don't need a fancy platform. You need a flow. Set up a welcome series and an abandoned-cart sequence on whatever's cheapest or free, and pour your energy into traffic. That's an estimate based on what I've seen, not a law of physics, but the logic holds: with a tiny list, automation revenue is rounding-error money. The inflection point is when you can see repeat purchases starting to happen on their own. Once 20–30% of your orders come from returning customers, every email you send compounds. That's usually somewhere north of $10k–$15k a month for most stores. SMS I'd add later still, once email is humming and you've got the budget for per-message credits, because SMS is consent-heavy and you can torch goodwill fast if you blast it.

Chart: Email and SMS ROI benchmarks versus monthly tool cost at 10,000 contacts. ROI figures are industry averages, not guarantees.
Chart by author. ROI figures from Litmus and Omnisend benchmarks (averages, label as estimates); tool costs from each vendor's 2025 pricing pages, approximate at the 10k tier.

The three tools, side by side

Klaviyo, Mailchimp, and Omnisend are the names that come up every single time. They are genuinely different animals. Prices below are list prices at a 10,000-contact tier pulled from each vendor's pricing page, and they shift, so verify before you commit.

Tool Best for Price ~10k contacts Ecommerce depth SMS Who it fits
Klaviyo Ecommerce-first brands on Shopify ~\$150/mo (email) Deepest. Built for stores; real-time Shopify sync, browse-abandon, predictive analytics Native, credit-based add-on; strong Growth-stage stores serious about owned revenue
Mailchimp General newsletters, light commerce ~\$135/mo (Standard) Bolted-on. Rocky Shopify history; fine for simple sends Add-on, weaker for ecom flows Content brands, B2B, stores where email is a side dish
Omnisend Email + SMS together, value ~\$99/mo (Standard) Strong and ecom-focused; pre-built automations Built in from the Standard plan; bonus credits on Pro Budget-conscious DTC wanting both channels in one bill

Evaluating them like a real buyer

Klaviyo is the one most serious ecommerce operators end up on, and for a reason. Its Shopify integration is the deepest of any third-party platform, syncing orders, products, and on-site browsing in real time, which unlocks stuff like browse-abandonment that the others fumble.[4] The catch is cost and a billing change. Since February 2025, Klaviyo bills on all active profiles, not just the ones you email, so a bloated list can spike your bill overnight.[5] Clean your list before you migrate. Mailchimp is the friendly generalist that got into ecommerce late. It's cheaper at small contact counts and the editor is lovely, but its Shopify integration has a famously rocky past after a 2019 dispute, and its automation depth just isn't built for revenue-driven flows.[6] If email is a small slice of your business, it's genuinely fine. If email is your growth engine, you'll outgrow it. Omnisend is the value play I quietly recommend a lot. SMS is baked in from the Standard plan at $16/mo for 500 contacts, the Pro plan at $59/mo throws in bonus SMS credits equal to your monthly fee, and the ecommerce automations are pre-built.[7] For a DTC brand that wants email and SMS on one invoice without Klaviyo's price tag, it's the sensible middle. If you'd rather not bolt three tools onto your store at all, an all-in-one platform like Sellarix folds owned-audience marketing into the same place you run the storefront, which spares you one more integration to babysit. Worth a look if consolidation is your goal, though a dedicated tool still wins on raw depth today.

The takeaway

Don't add email and SMS because a blog told you to. Add them when you can see returning customers in your numbers, because that's when the compounding starts. Start with email and one or two flows, pick Omnisend if budget and SMS-together matter or Klaviyo if you're all-in on ecommerce, and keep Mailchimp on the bench unless email is a sideline. SMS comes after email is working, not before. So where are you actually sitting right now: still renting your customers, or finally ready to own the list?

Sources

Person checking phone notifications, the channel SMS lives in. Photo: Pexels, free license.

Replace six tools with one

Join the waitlist to be first on the platform, or book a demo.

Join the waitlistBook a demo