10 Best Klaviyo Email Marketing Agencies for Ecommerce
The best Klaviyo email marketing agency puts experienced people on your account, shows results from stores like yours, and reports revenue in a way you can check inside Klaviyo itself. Chromex suits small and mid-sized stores that want a done-for-you team and performance-based pricing. Flowium suits brands that like a documented process. The Email Marketers suits eight-figure brands that want senior-only staff. Underground Ecom suits large brands that need layered teams, and InboxArmy suits tight budgets.
Most stores that go looking for an agency are in the same spot. Traffic and ad spend are already there, but email brings in under 10% of revenue, the flows are thin or broken, and the last freelancer left generic templates and reports nobody could follow. Every agency pitch promises big numbers, and few explain how those numbers are measured.
This guide compares 10 agencies on what they do, who they suit, and what they charge, using public information and reported pricing. We are Chromex, so we list ourselves first and say so plainly. After the list you will find a cost comparison, a worked example of whether a retainer pays for itself, and a checklist for choosing and vetting an agency.
What a Klaviyo agency does and how we compared them
A Klaviyo agency plans, builds and runs your email and SMS programs inside Klaviyo, so you get strategy, flows, campaigns, design, testing and reporting without hiring a full team. The platform is the tool. The agency is the people who use it well.
What Klaviyo does and what an agency adds
Klaviyo is an ecommerce marketing platform that sends email and SMS based on what shoppers do in your store. So yes, Klaviyo does email marketing, but it does not decide your segments, write your copy, or fix your deliverability for you. Its own platform fee is separate from any agency fee, and it scales with how many profiles you message and how much SMS you send. Check Klaviyo's current pricing page for your list size.
Is Klaviyo the best option? For most online stores it is a strong default, and Omnisend and Mailchimp are the tools it is most often compared with. The tool matters less than the operator. A good agency can also work in other platforms, which is useful if you ever switch.
The platform sends the emails, but the agency decides what gets sent, to whom, and why.
The criteria behind this list
We compared each agency on the same six points:
- Who works on your account. Named, senior, meetable people beat anonymous delivery teams.
- Specialization. Is email and SMS the core craft, or one service among many?
- Proof. Named clients and results that can be checked against real Klaviyo data.
- Pricing clarity. Published rates or honest minimums beat "book a call to find out."
- Deliverability. A plan for inbox placement, list hygiene and sender reputation.
- Contract terms. Month-to-month beats a long lock-in.
We used public pages, agency statements and reported pricing. Where sources disagreed, we say so.
What Klaviyo partner tiers tell you
Klaviyo certifies agencies in tiers: Silver, Gold, Platinum and Elite, with a "Master" label for agencies that actively manage client accounts. Higher tiers usually mean earlier access to features and closer contact with Klaviyo's team.
A tier is a signal, not a guarantee. It reflects how established an agency is and how many accounts it manages, not whether it fits your brand. Check the current tier in Klaviyo's partner directory instead of trusting a badge on an agency website.
1. Chromex
Chromex is a specialist email and SMS agency for ecommerce brands, and it runs the work as a four-step process with fixed timing. We are the publisher of this guide, so weigh our entry with that in mind.
What it does
We take over your email and SMS program and run it end to end. Founder Farhan Uz Zaman started Chromex in 2021, and it is a lean team of email marketers, designers and strategists. Every email is designed from scratch, with no templates, and reporting is written in plain language. Work happens in Klaviyo and Omnisend, and Chromex is an official Omnisend partner.
The process runs in four steps:
- Analyze (days 1 to 5): a full email audit, deliverability fixes, market and competitor insights, and a 60-day action plan.
- Create (days 5 to 15): all 8 core automated email sequences plus a high-converting sign-up form for list growth.
- Kickoff (around day 15): a campaign calendar and value-based campaigns that support the automations.
- Optimize (day 30 onward): mass testing of every part of the email system so revenue compounds.
Who it suits
Chromex suits founders and growth managers at small to mid-sized ecommerce stores that already have traffic and ad spend but get under 10% of revenue from email. It also suits brands burned by unreliable freelancers or agencies that sold a template package.
Chromex reports that email drives an average of 45% of its clients' monthly revenue, with 92% client retention and $14M+ in email-attributed revenue. One client brand has generated $500,000+ with email driving nearly 70% of its monthly revenue. As with any agency's figures, ask how attribution is set.
If email is under 10% of your revenue and nobody owns it, a fixed timeline that has your core flows built by day 15 gets you moving faster than an open-ended retainer.
Pricing and trade-offs
Chromex prices on a transparent, performance-based model rather than fixed packages, so you will not find a rate card. You get a quote after a call, which suits brands that want pay tied to results but means no number to compare up front.
The trade-offs are focus and age. Chromex does email and SMS, so it will not run your ads or rebuild your site. It is also younger than several agencies below, so judge it on the audit and the first 15 days, which show quickly whether the work is right.
2. Flowium
Flowium is a Klaviyo Master Elite agency that delivers email and SMS through standardized account pods and repeatable processes. It is the pick for brands that want a documented, predictable engagement.
What it does
Andriy Boychuk founded Flowium in 2017. Audits, flow builds and campaign calendars follow strict, templated processes, backed by one of the larger libraries of educational content in the space.
- Tier: Klaviyo Master Elite.
- Team model: distributed pods of roughly six people.
- Scope: email and SMS only, with no paid media, CRO or development.
Who it suits
Flowium suits growth-stage and mid-market brands. Roughly 80% of its clients are mid-market, and Clutch shows 23 reviews with a strong record. If you value a systematized process and clear documentation, you will likely be happy.
Brands that want bespoke, individually tailored strategy may find the templated approach constraining. A minority of reviews mention time zone friction because the team is globally distributed, so ask about meeting overlap with your hours.
Pricing and trade-offs
Reported figures vary. Clutch-based reports put minimum projects from $1,000 and typical retainers between $2,500 and $10,000 per month, while another source puts full retention work at $8,000 to $18,000. Get a written quote for your scope.
The trade-off is flexibility. A system that runs well for most accounts can be slow to bend for unusual ones, and design speed may depend on your in-house team.
Choose Flowium for process and documentation, and expect less room for one-off, custom strategy.
3. The Email Marketers
The Email Marketers is a Los Angeles retention agency that works with eight-figure ecommerce brands and staffs every account with senior specialists. It is a good fit when you want experienced people and a wider retention scope than email alone.
What it does
Beyond email and SMS, the agency runs push, direct mail, subscriptions, memberships, loyalty and referral programs. Clients get a monthly revenue forecast, a rolling 90-day roadmap and board-style reports. The agency says it generated more than $103 million in attributed client revenue in 2025.
- Tier: Klaviyo Platinum.
- Team model: five senior specialists per account, US-led.
- Scope: retention only, with no paid acquisition, SEO or site development.
Who it suits
It suits eight-figure DTC brands that want senior-only staffing and a retention strategy tied to lifetime value. The agency publishes its case studies and open about its fit limits, which helps you judge the match.
By its own account, brands under seven figures are better served elsewhere. It offers a coaching program called Retention Lab for smaller brands with a capable person in-house.
Pricing and trade-offs
Pricing is published: it starts at $4,400 per month, averages $6,500, and reaches $12,999 on the largest published package. That is premium pricing, and it reflects the senior-only team.
The trade-off is cost and capacity. Expect a selective intake, and plan to compare the price against smaller specialists if your revenue is below the target range.
You pay premium rates here to avoid junior staff, which only makes sense if your revenue can absorb it.
4. Underground Ecom
Underground Ecom is a London-based retention agency with more than 100 people, built for large brands that want layered team coverage. It describes itself as Klaviyo's largest Elite partner and was named Klaviyo's Agency Partner of the Year for EMEA in 2025.
What it does
Each account gets a layered team: a CRM director, a CRM manager, designers and copywriters, plus a senior strategy layer. Services cover flows, campaigns, SMS, WhatsApp, loyalty integration and migrations from other platforms. It also runs a proprietary benchmarking tool, Underground Insights, built on data from 500+ brands and included in every active retainer.
- Tier: Klaviyo Elite.
- Team model: 100+ staff with layered account teams.
- Notable clients: AG1, Huda Beauty and Oh Polly.
Who it suits
It suits eight- to ten-figure brands that want enterprise-grade coverage and benchmarking against similar brands. If you sell across several markets or need many channels managed at once, the bench depth is a real advantage.
Smaller brands may find a layered structure heavy. If you want weekly contact with one senior person, ask exactly who that is. US brands should also confirm time zone overlap.
Pricing and trade-offs
Pricing is unpublished and, for work at this scale, effectively a five-figure monthly commitment. Treat it as an enterprise purchase and ask for a scoped proposal.
The trade-off is distance. Layers bring consistency and capacity, but fewer direct conversations with the senior strategist. Ask for named client references you can call.
Underground Ecom suits brands that need a big team and benchmarks, not a hands-on boutique.
5. Chronos Agency
Chronos Agency is a Singapore-headquartered Klaviyo Elite Master partner of roughly 80 people. It stands out for adding push notifications to email and SMS and for a large public review base.
What it does
Chronos was founded in 2017 and says it has served 500+ brands and driven $400M+ in email-attributed revenue. Those are agency claims, so ask how attribution is set. It runs email, SMS and push as one program.
- Tier: Klaviyo Elite Master.
- Team model: about 80 people, with delivery centered in Asia.
- Reviews: 58 on Clutch.
Who it suits
It suits fast-scaling brands that want email, SMS and push handled together and value an efficient, volume-oriented model. A large review base makes reference-checking easier than with most boutiques.
Ask the fair question of any distributed team: who exactly is my strategist, what hours do they overlap with mine, and how senior are they? Chronos states that its client teams work US hours for US brands.
Pricing and trade-offs
Starter retainers are reported at roughly $4,000 to $5,000 per month. Onboarding has been reported at four to six weeks before the first campaign ships, so plan for a slower first quarter.
The trade-off is that volume-oriented models can mean less bespoke attention. Check how your strategist is assigned and what the escalation path looks like.
Chronos gives you broad channel coverage at mid-market prices, as long as you confirm who runs your account.
6. Fuel Made
Fuel Made is a Shopify-only agency of about 17 people, all senior and US-based, that combines Klaviyo email with Shopify Plus design, development and CRO. It is the pick when your email problems are tangled up with site problems.
What it does
The team has worked exclusively in Shopify since 2010 and holds Klaviyo Master Elite status. If product pages are slow, checkout leaks, or signup capture is poor, one team can fix both sides.
- Tier: Klaviyo Master Elite.
- Team model: about 17 people, all senior, all US.
- Scope: Shopify Plus build, CRO and email.
Who it suits
It suits Shopify Plus brands whose Klaviyo performance is held back by messy data: missing events, broken product feeds or bad customer tags. You get one accountable team instead of coordinating a developer and an email shop.
It does not suit stores on other platforms. Capacity is small, so ask about timelines before you plan a launch around them.
Pricing and trade-offs
Clutch lists $5,000 minimums at $150 to $199 per hour. Pricing leans toward projects, so a rolling monthly retainer may take negotiation.
The classic risk with a broad agency is being average at everything. Fuel Made's credentials on both platforms look real, so test the claim: ask for email-specific case studies, not combined ones.
Hire Fuel Made when the store and the email program are one problem, not two.
7. Homestead Studio
Homestead Studio is a Wisconsin-based full-funnel agency that splits its work across email, SMS, paid media, CRO and web design. It was named Klaviyo's Americas Agency Partner of the Year for 2025.
What it does
If you want one agency accountable for both acquisition and retention economics, Homestead is the strongest option on this list. Creative is built into the work, which suits brands with a defined visual identity.
- Tier: Klaviyo Master Elite.
- Team model: full-funnel team.
- Scope: email is about 20% of its work.
Who it suits
It suits brand-forward, higher-order-value brands, such as lifestyle and apparel stores, where email design has to match the site. Brands that want paid and email planned together also benefit.
Pure email depth trails the dedicated specialists above. The agency was acquired by Verndale, and acquisitions can bring change, so ask how the email practice is staffed today.
Pricing and trade-offs
Clutch lists $5,000 minimums at $200 to $300 per hour, the highest hourly band here. One source reports monthly floors of $10,000 or more, so confirm in writing.
The trade-off is scope. You pay for a broad team, which is wasteful if all you need is Klaviyo run well.
Homestead is worth the premium only if you want acquisition and retention under one roof.
8. Magnet Monster
Magnet Monster is a UK-based agency founded in 2018 by Adam Kitchen, known for one flat monthly fee across email, SMS, WhatsApp and direct mail. It is a fit for brands that dislike line-item billing.
What it does
The flat fee bundles every retention channel, and the founder teaches publicly on LinkedIn and podcasts, which shows how the agency thinks. Clients include Waterdrop.
- Tier: top-level Klaviyo partner (listings vary between Master Elite and Platinum Master, so verify).
- Team model: founder-led.
- Scope: email, SMS, WhatsApp and direct mail.
Who it suits
It suits brands that want predictable billing and a multi-channel program without negotiating each addition. Brands with a physical direct mail or WhatsApp angle get the most from the bundle.
US brands should factor in the UK base when planning calls and approvals. A founder-led team can also mean limited capacity as it grows.
Pricing and trade-offs
The flat monthly fee is the draw, though the figure is not published. Flat-fee "unlimited" models usually mean a defined delivery cadence, not unbounded bespoke work, so ask exactly what the cadence includes.
Request a written scope that lists campaigns per month, flow builds and revision limits.
A flat fee is only a bargain if you know exactly what it covers each month.
9. Sticky Digital
Sticky Digital is a female-founded California retention boutique, co-founded by Nikki Tooman and Mariel Kilroy. It works only with DTC brands whose customers are mostly women.
What it does
The focus is the point: beauty, wellness, food and beverage, and apparel. Klaviyo's directory lists it at Platinum Master tier. The team is small and does retention only.
- Tier: Klaviyo Platinum Master.
- Team model: small boutique.
- Scope: email and SMS retention for DTC.
Who it suits
It suits beauty, wellness and food brands that want a specialist who already knows how their customers buy. That pattern-matching speeds up strategy and copy.
Brands outside its verticals lose that advantage. A small team also means limited capacity and possible waitlists, so ask when your build could start.
Pricing and trade-offs
Clutch lists a $1,000 minimum at $100 to $149 per hour, the most accessible specialist entry point here. Its Clutch profile currently shows no reviews, so ask for references directly.
The trade-off is scale. A boutique cannot absorb a sudden jump in scope the way a 100-person agency can.
Sticky Digital is a low-cost, niche specialist, so confirm references before signing.
10. InboxArmy
InboxArmy is a Texas-based email production agency with 120+ people that supports 40+ platforms, including Klaviyo. It is built for volume and budget, not for deep DTC strategy.
What it does
The team produces templates and executes campaigns at scale, which helps if you are mid-migration between platforms or run more than one email service provider. It holds a 4.9 rating across 71 Clutch reviews.
- Tier: Klaviyo Silver Master, the lowest on this list.
- Team model: 120+ production staff.
- Scope: template production and campaign execution.
Who it suits
It suits budget-conscious brands and teams that already know their strategy and need dependable hands to build and send. In-house marketers who need extra production capacity get good value.
If you need someone to decide what your retention program should be, look at the specialists above. Klaviyo is one of 40+ platforms here, not the core craft.
Pricing and trade-offs
Managed services start at roughly $1,500 per month, published on its pricing page, which makes it the cheapest entry on this list.
The trade-off is strategy. You are buying production capacity, and both are valid purchases as long as you know which one you need.
InboxArmy is a production partner at a low price, not a retention strategist.
What a Klaviyo email marketing agency costs
A Klaviyo email marketing agency typically costs between $1,500 and $18,000 or more per month, depending on the model. One source puts retainers at $3,000 to $25,000, with most mid-market brands landing between $6,000 and $12,000.
Reported pricing side by side
The table below collects published and reported figures. Treat them as starting points, because scope changes everything.
| Agency | Reported starting point | Model notes |
|---|---|---|
| InboxArmy | About $1,500/month | Production-focused managed services |
| Sticky Digital | $1,000 minimum | $100 to $149/hour on Clutch |
| Flowium | $2,500 to $10,000/month | Reported retainers, minimums from $1,000 |
| Chronos Agency | About $4,000 to $5,000/month | Reported starter retainers |
| The Email Marketers | $4,400/month, average $6,500 | Up to $12,999 on largest package |
| Fuel Made | $5,000+ projects | $150 to $199/hour on Clutch |
| Homestead Studio | $5,000+ minimums | $200 to $300/hour on Clutch |
| Magnet Monster | Flat monthly fee | Amount not published |
| Underground Ecom | Unpublished | Enterprise scale |
| Chromex | Quote after a call | Performance-based, no fixed packages |
Worked example: does a retainer pay for itself?
Take a store with $3M in annual revenue where email brings in 10%, or $300,000. If a good program lifts email to 25%, that is $750,000, a gain of $450,000. At a 40% gross margin, the gain is worth $180,000.
A $6,000 monthly retainer costs $72,000 a year. In this illustration the agency fee is 40% of the extra margin, which leaves a healthy return. Part of any lift is shifted rather than new revenue, so discount the gain before you decide.
Pricing models to watch
Retainers are predictable. Revenue share aligns incentives on paper but can get expensive as you grow, and it gives the agency a reason to widen the attribution window and count opens. If you go that route, insist on a minimum retainer and agree the attribution rules in writing.
The fee only makes sense when it is measured against margin you can verify, not against attributed revenue alone.
How to choose and vet a Klaviyo agency
Choose by matching the agency type to your stage, then test the shortlist with direct questions. A clean logo wall tells you less than a straight answer about who will build your flows.
Match the agency to your stage
Match by need, not by reputation:
- Email under 10% of revenue, no in-house owner: a specialist done-for-you agency such as Chromex, Flowium or Sticky Digital.
- Eight-figure brand wanting senior-only staff: The Email Marketers.
- Large or multi-market brand: Underground Ecom or Chronos.
- Store problems tied to email problems: Fuel Made or Homestead Studio.
- Strategy in place, production needed: InboxArmy.
Questions to ask on the sales call
Ask for specifics and listen for hedging:
- Who will build my flows and write my copy, and can I meet them?
- What is the attribution window, and does it count opens or only clicks?
- What is your deliverability plan, including authentication and list hygiene?
- Which clients do best with you, and which do not?
- What happens in the first 60 days?
- Can I keep full access to my Klaviyo account and raw data?
An agency that admits its weak spots will be honest when your numbers dip.
Red flags to walk away from
Watch for these:
- Open-based attribution. Mail privacy features auto-open many emails, so opens inflate results. Judge on clicks and revenue.
- The pitch team is not the delivery team.
- Template flows pitched before any discovery of your products, order value or repeat rate.
- Revenue share with no floor.
- Long lock-ins or "we need a year to see results."
- Slide-deck reporting with no access to your own Klaviyo account.
How fast to expect results
Timelines differ by agency. Sources report first revenue lifts in two to three weeks from quick-win campaigns, and onboarding of four to eight weeks at larger shops. Sustained gains usually take 60 to 90 days as flows and segmentation mature.
Ask for the schedule in writing. Chromex, for example, commits to a full audit by day 5 and the 8 core flows by day 15.
Picking your Klaviyo partner
The right agency depends on your revenue stage, your platform and how much of the work you want to hand off. Specialists suit stores where email is still a small share of revenue. Full-funnel agencies suit brands whose store and email problems overlap, and production shops suit teams that already know their strategy.
Whichever you pick, check the Klaviyo tier yourself, ask how attribution is set, and get scope and price in writing before you sign. A good agency will answer all of that without hesitation.
If you want a done-for-you team with a clear timeline from audit to testing and performance-based pricing, book a Chromex audit for your Klaviyo or Omnisend program.