Ever sign up for texts, complete a purchase, then get the same 10 percent code by SMS and email? That duplication drains budget and irritates shoppers. Below are eight agencies that run both channels, followed by a simple guide to which message belongs in which channel and a short compliance note.
1. InboxArmy: best for email and SMS programs on any platform
InboxArmy is a full-service email marketing agency that does email and SMS only, across 40+ ESPs and 25+ industries. For texts, InboxArmy handles SMS strategy, segmentation, campaign management and automation, compliance and privacy management, and reporting, and integrates SMS with email campaigns. A cart abandonment automation for RC Juice increased monthly revenue by 400 percent, and London Store recorded 1,100 percent email revenue growth in nine months. Site-wide, the agency reports $1B+ in email revenue and $115M+ in SMS revenue generated. Its managed-service minimum is $1,500 per month.
2. First Pier: best for Shopify stores that want store and lifecycle work from one team
First Pier is a Shopify and ecommerce growth agency in Portland, Maine, that lists Klaviyo email and SMS marketing among its services. For Lamey Wellehan, a six-store Maine shoe retailer, it migrated and warmed the email list into Klaviyo, built a welcome series and abandonment flows, and split profiles into engaged, at-risk, unengaged, and staff segments. It also helped Wyman’s build a DTC channel that, per the client, went from essentially $0 to multimillion-dollar sales.
3. Pilothouse: best for brands that want email and SMS run alongside paid media
Pilothouse, based in Victoria, British Columbia, runs acquisition, retention, creative, and CRO under one roof. Its email and SMS lifecycle work runs on Klaviyo, Postscript, and Attentive, measured with GA4 and post-purchase surveys. For Journee, after an IP re-warm and a flow rebuild, Pilothouse reports a 239 percent increase in email-attributed revenue 278 percent more repeat revenue, and 254 percent more revenue per email sent in the first six months, year over year.
4. Sticky Digital: best for subscription, replenishment, and loyalty-driven brands
Sticky Digital is a Klaviyo Platinum Partner that works only in retention: email, SMS, loyalty, and subscription. It builds churn-reduction flows, cancellation interventions, and win-back sequences for brands on Recharge, Stay.ai, and Ordergroove. Nest New York grew its subscription program more than 200 percent in one year after the agency implemented subscription adoption and win-back strategies. The agency says it takes on a small number of clients at a time.
5. eCom2Win: best for growth-stage stores on Klaviyo or Omnisend
eCom2Win is an email and SMS agency that reports 250+ ecommerce brands served and $31M+ generated for clients, working on Klaviyo or Omnisend. Omnisend’s customer story on the agency describes a client migrated from Klaviyo to Omnisend in 24 hours. Its first Black Friday on Omnisend produced more than $113,000 in attributed email revenue, 53 percent of the brand’s total store revenue for that period.
6. Sweat Pants Agency: best for brands craving senior-led specialist support
Sweat Pants Agency, based in Nashville, works with DTC and subscription brands from $3M to $100M+, and clients work directly with senior operators. It runs month to month with no setup fees. Condition 1, a Texas maker of protective cases, recorded 679.9 percent revenue growth in its 2025 Black Friday Cyber Monday campaign, with SMS flows contributing 15.7 percent of attributed revenue. An organic-food brand’s first Earth Day sale with the agency produced about $32,000, with SMS driving about $10,500 of it.
7. Flowium: best for multi-channel retention programs
Flowium is a Klaviyo Master Elite partner based in Staten Island, New York, and a 2025 Inc. 5000 honoree. It runs email, SMS, push, WhatsApp, RCS, Instagram DM, and direct mail, and offers a free, no-commitment diagnosis. Klaviyo’s case study on Smile Brilliant, a Flowium client since 2023, reports a 39x ROI over the past year. Pricing is quoted after scoping, with a two-year price lock and no long-term contracts.
8. Chronos Agency: best for established DTC brands that want a multi-specialist team
Chronos, founded in 2017 with offices in Singapore and Sydney, is a Klaviyo Master Elite partner that reports work with 500+ DTC brands and $400M+ in attributable revenue. It assigns 6+ specialists per account and focuses on brands doing $100K+ a month. Organifi partnered with Chronos to revive its email and SMS programs and recorded a 234 percent increase in email revenue over six months. Kiyoko Beauty grew its email revenue 3.4x during BFCM 2024.
Which message goes by text, which by email?
- Welcome: send a confirmation text the instant someone opts in, then an email within minutes with the brand story and how to redeem the offer. Use one discount code across both.Â
- Cart abandonment: email first with product images, then a one-line text a few hours later if the cart still sits. Stop every send once the order posts.Â
- Promotions: email explains the sale; SMS reminds high-intent segments before it closes.Â
- Transactional: email owns receipts and tracking; text only urgent updates such as a delivery change or payment failure.Â
- Retention: email rebuilds value; save texts for replenishment timing and lapsed VIPs.
A compliance note for Canadian and U.S. lists
Canada’s Anti-Spam Legislation (CASL) covers texts as well as email: each commercial message needs consent, sender identification, and an unsubscribe mechanism, and unsubscribe requests must take effect within 10 business days. The CRTC enforces the Act, with penalties of up to $10 million per violation for a business. In the U.S., ask who owns TCPA consent records and 10DLC registration with The Campaign Registry before the first text goes out.
Conclusion
The right agency decides which message deserves the speed of a text and which needs the depth of email, then runs both from one calendar so no shopper gets the same promo twice. Shortlist two or three, ask each for a 90-day sample calendar, and judge them on incremental revenue, not vanity attribution.
