Looking for an Underground Ecom alternative? Four agencies cover the realistic options. YOCTO (us), if you want retention run on a published methodology, with real depth on subscriptions. Email Kong, if you want email, SMS and WhatsApp handled by a small in-house team. Everboost, if you’re a CPG brand with a big segment email can’t reach. Enchant, if you’re an established retailer with a complex catalogue.
We compete with Underground Ecom, so read this knowing that. Every fact about them on this page comes from their own website and public listings. If anything here is wrong or out of date, tell us and we’ll correct it.
One thing most alternatives pages skip: the criteria. Ours are written out below, including the one that matters most and gets checked least – whether the agency runs on a published methodology or keeps its process in-house.
Key takeaways
- Why brands look elsewhere. In the accounts we audit, brands switching away from very large agencies usually cite structural fit – team size, standardised delivery, strategy cadence – rather than work quality. That’s an observation from our side of the fence; weigh it accordingly.
- Four real alternatives, split by operating model. YOCTO (methodology-led, deepest on subscriptions), Email Kong (small in-house team, adds WhatsApp), Everboost (CPG retention plus direct mail), Enchant (eCRM for established multichannel retailers). Everything else in the directories is a variation on one of these.
- The tier is a tie; the methodology is the difference. YOCTO holds the same Klaviyo Elite Master tier – top 0.0025% of partners globally as of July 2026 – but runs every account on a published system: the LTV Parthenon. Three pillars, nine numbers, published in Forbes, and every piece of work judged against them.
- Demand proof the agency didn’t write itself. Klaviyo, Skio and Loop have each independently published case studies on YOCTO client work. A platform only puts its name on work that makes the platform look good – the hardest kind of proof to fake.
- Range is the test of a methodology. The same system produced $1M a week from email for ColonBroom (direct response) and +370% flow revenue for Dandelion Chocolate (luxury). A system that only works on one kind of brand is a playbook with better branding.
- Switching is a handover problem, not a gamble. Audit first, confirm you own your accounts, never pause live flows, freeze a 90-day baseline, and price the move – the five-step plan at the end of this page keeps revenue flowing through the transition.
What does Underground Ecom offer?
Underground Ecom is a London retention agency with what it describes as delivery hubs in Belgrade and Cape Town and a team it lists at 150-plus specialists. It runs email and SMS end to end on Klaviyo – strategy, content, testing, technical support, reporting – and holds Klaviyo’s Elite Master partner tier as of July 2026, and was named Klaviyo’s EMEA Agency Partner of the Year for 2025. Named clients include Virgin, Oh Polly, Surreal and Osprey.
The offer is coverage: a fully staffed external department that takes the whole channel off your plate. If that’s what you’re buying, they deliver it – a large, capable team with the coverage and enterprise track record to back it. The rest of this page is for brands whose needs are more subscription-specific.
When a specialist fits better than a full-service team
We audit accounts coming out of large agencies every month – many agencies, not one. Three patterns repeat, and they’re about what scale tends to produce, not about any single firm’s conduct.
Ask how the strategy evolves
In any long engagement, the useful question is how the plan changes after the first 90 days. Ask to see how last quarter’s roadmap differed from this quarter’s.
Know who runs your account after month one
At large agencies, senior strategists typically lead the pitch and structured teams run delivery – that’s how scale usually staffs, and plenty of brands prefer a deep bench. If the pitch team was your reason for signing anywhere, ask who builds your strategy in week twelve.
Ask how much is bespoke versus standardised
Big agencies standardise: same flow structure, same templates, same testing roadmap on every account. That produces strong baselines. Subscription brands have extra levers – churn, failed payments, lifetime value growth – that a standard email playbook isn’t built to reach.
How should you judge an Underground Ecom alternative?
Four checks separate a real alternative from a lookalike with a smaller headcount. Run every agency on your shortlist through them, including us.
- An owned methodology. Ask what the agency’s methodology is called and where it’s published. Some answer with a process diagram built for the pitch; a named, published methodology is a different thing. An agency that has done the thinking writes it down, names it, and defends it in public – because a real methodology survives scrutiny and a playbook doesn’t. Ask this in the first call, before the case studies come out.
- Proof published by someone else. Self-published case studies are useful; independently published ones clear a higher bar. Look for work the platforms chose to publish under their own name – Klaviyo, Skio, Loop, Recharge. A platform puts its logo on a story only when the work makes the platform look good.
- Partner tier, checked by you. Klaviyo’s partner directory is public. Two minutes there tells you whether the tier on the agency’s website is current. Tier isn’t everything, but it’s one of the few signals an agency can’t award itself.
- Depth in your revenue model. Subscription brands live or die on churn, failed payments and order-to-subscription conversion. Repeat-purchase brands live on winback windows and time between orders. An agency built around a different revenue model may need time to get up to speed on yours.
1. YOCTO – the methodology-led alternative
- HQ: Cyprus, with a London presence
- Klaviyo tier: Elite Master – top 0.0025% of partners globally, July 2026
- Focus: DTC and CPG brands; deepest on subscriptions
- Pick us if: You want your retention run on a system you can read, question and hold us to
YOCTO is a customer retention agency for DTC and CPG brands. The work covers email, SMS, WhatsApp marketing and full lifecycle programs – flows, campaigns, segmentation, deliverability – and the deepest part of it is subscription marketing: churn, failed payments, win-back, lifetime value growth. What separates us from Underground Ecom isn’t headcount. It’s that every account runs on a methodology we built, named and published.
The LTV Parthenon
The LTV Parthenon is YOCTO’s framework for growing customer lifetime value, published in Forbes in January 2026. Three pillars: grow the base, keep them, spend more. Nine numbers sit under the pillars, and every campaign, flow and test on the account is judged against those nine. If a piece of work doesn’t move one of them, it doesn’t ship.
Two moves inside the Parthenon show how it thinks. First, billing moments become gifting moments: the subscription charge notification – the message most brands send as a cold receipt, at the exact point cancellation risk spikes – gets rebuilt as something worth opening: a gift, an upgrade, a reason to stay. Second, motivation decay: subscribers rarely cancel out of nowhere. Motivation fades over weeks, it shows up in the data before it shows up in a cancel click, and the system intervenes early, when saving the subscriber is still cheap.
The range is the proof that it’s a methodology and not a playbook. The same system produced $1M a week in email revenue for ColonBroom, a direct-response wellness brand, and +370% flow revenue for Dandelion Chocolate, a luxury bean-to-bar chocolate maker. Playbooks don’t transfer between those two worlds. First principles do.
The thinking isn’t locked in a proposal deck, either. George Kapernaros, YOCTO’s founder, publishes it: the Parthenon in Forbes, subscription strategy in Fast Company, and ongoing work through the Forbes Business Council and Klaviyo’s partner ecosystem. You can read the methodology before you ever book a call, and hold us to it afterwards.
The results – starting with the ones we didn’t publish
Three case studies about YOCTO client work were published by the platforms themselves. A platform puts its name on a story only when the work makes the platform look good, which makes these the hardest proof on this page to argue with.
Klaviyo × Mira. Mira, a women’s health brand, had signups arriving from an app, a blog, webinars and lead magnets – and sent them all the same generic emails. We built 85 flows in Klaviyo matched to how each person actually entered. Result, published by Klaviyo: email and SMS revenue up 252% in six months, reaching 52% of total revenue, with flows driving half of it.
Skio × Gratsi. Gratsi, a premium boxed wine brand, needed one-time buyers turned into subscribers without discount-bombing the list. Subscriber perks were made visible at the exact moment of cancellation, and win-backs were automated at scale. Result, published by Skio: cancellations cut 48%, reactivations up 208%, a 47.2% revenue lift across a 500K-plus list – and active subscriptions more than doubled inside a year.
Loop × Evereden. Evereden, a premium family skincare brand, had loyal repeat buyers but almost no subscribers. A two-tier subscription price, subscriber-first promo campaigns and bundle testing changed that. Result, published by Loop: 8× subscription growth in three months – in December, the slowest season for beauty subscriptions – with bundles lifting average order value 30% above the store norm.
Then the ones we did publish:
- Healf: email revenue up 5×. Healf is now first on the FT1000 list of Europe’s fastest-growing companies for 2026.
- Zapply UK: 469% quarterly growth from its subscription engine.
- Jimmy Joy: revenue up 94.9%.
- ColonBroom: $1M a week from email, sustained.
- BetterMe: email and SMS revenue up 400%, built from scratch.
- Dandelion Chocolate: revenue up 370% on flows.
There are 28-plus case studies published on the site, and more are added regularly.
Healf is the fastest-growing company in Europe on the 2026 FT1000. Gratsi is America’s #1 fastest-growing boxed wine brand by sales revenue, per Nielsen. Different continents, different categories, same setup: a brand that treats retention as a growth engine, and our system underneath it. We don’t claim credit for either company’s trajectory – but twice is a pattern, and the pattern is the point.
Arman Uddin, who runs growth at Healf, on working with us: it is “refreshing to see YOCTO keep and deliver with the pace.” And Ashley Coleman, founder and CEO of Boujee Hippie: “revenue is up, the numbers keep getting better, and the cost has gotten lower.” Her messaging costs fell 34% while revenue rose 31%.
Who we don’t take: hospitality, B2B, and brands that mainly want a big team producing high volumes of creative. That’s not what we’re built for. What we are built for is on the homepage: Klaviyo email marketing agency work with subscriptions at the core.
2. Email Kong – small in-house team for email, SMS and WhatsApp
London. Klaviyo Platinum, the top 2.5% of partners. Founded by Bogdan Mihalache and Cynthia de Gelder, with more than 140 DTC brands served and all work done in-house – no outsourcing, no white-label delivery. They cover WhatsApp and in-app messaging on top of email and SMS, which is more channel range than most agencies their size, and they rebuild strategy per client from margins and buying behaviour rather than reusing a template.
Pick them if you’re a DTC brand past roughly $2M a year and channel breadth matters more to you than subscription depth. They’re a younger shop, and Platinum is a tier below Elite Master. Enterprise procurement teams may want a longer track record; founder-led brands generally won’t care.
3. Everboost – CPG retention plus direct mail
A UK boutique that works only with seven-to-eight-figure CPG brands – 50-plus served so far. Their distinct tool is direct mail: they send physical mail to churned and never-subscribed customers – people email can’t reach. The rest of the offer is behaviour-based flows, campaigns, sign-up form testing and subscription work, run through a four-stage process they call ECHO. Salt Grooming’s time between orders dropped from 139 days to 58 with them; Mersey Raw, a raw pet food subscription brand, cut churn 13%.
Pick them if a big part of your customer file is unreachable by email. Small team, consumables only – apparel, hospitality and B2B are outside their lane.
4. Enchant – email and CRM for established retailers
London. Klaviyo Master Platinum partner for more than eight years, and a Klaviyo Klicks Award winner for automation work. The client list says what they’re for: QVC, Sealskinz, Herbalife, Cox & Cox, Hampers.com – brands with complex catalogues, seasonal trading calendars and legacy data. Where the rest of this page is built for fast-moving DTC, Enchant is built for retail estates where email has to coexist with merchandising plans and trading teams.
Pick them if you’re a multichannel retailer rather than a fast-scaling DTC brand. Subscriptions aren’t their focus, and the pace is set for bigger organisations.
Underground Ecom or YOCTO – which should you pick?
Stay with Underground Ecom, or choose them, if: you want one vendor covering every retention task with a big bench; you want breadth of coverage and a large dedicated team; or you have no in-house retention owner and need a full external department.
Choose YOCTO if: subscription revenue is a meaningful share of your business; you want the methodology behind your account written down where you can read it; or you judge an agency on lifetime value numbers rather than on how much it ships. If you’re still unsure after reading both columns above, book the audit – it exists for exactly this decision.
How do you switch email agencies without losing revenue?
Switching losses come from bad handovers, not bad choices. Five steps.
- Get an audit first. From whichever agency you’re considering, including us. The audit shows you how they think, and you keep it either way.
- Confirm what you own. Klaviyo admin access, sending domains, templates, integrations. Do this before you give notice.
- Don’t pause the flows. They keep earning through the handover. The incoming agency rebuilds against the live baseline, and nothing goes off until its replacement beats it in a split test. Agencies that ask you to switch everything off on day one are optimising for their convenience, not your revenue.
- Freeze a baseline. Ninety days of repeat rate, churn, email revenue share and revenue per recipient. Measure the new agency against it. Our LTV calculator gives you the upside number to hold them to.
- Price it. New retainer against current retainer against hiring in-house. Read a Klaviyo agency pricing guide before the sales calls. Then set an exit criterion with whoever you choose: the two or three numbers that, if they haven’t moved in 90 days, mean the engagement isn’t working.
What the first 90 days after switching look like
Weeks one and two: access, audit, and the frozen baseline. Weeks three to six: the new agency rebuilds flows against your live ones – nothing switched off, everything split-tested. Weeks seven to twelve: replacements that win go live, losers get killed, and the first report lands against the baseline you froze, not against a story. If the first 90 days don’t follow roughly this shape, ask why.
Frequently asked questions
Who are Underground Ecom’s main competitors?
In UK ecommerce retention: YOCTO (methodology-led, deepest on subscriptions), Email Kong (small in-house Klaviyo team), Everboost (CPG retention with direct mail) and Enchant (established retail eCRM). Directories list dozens more, but these four represent the distinct models – the rest are variations on one of them.
What is the LTV Parthenon?
YOCTO’s published framework for growing customer lifetime value. Three pillars – grow the base, keep them, spend more – with nine numbers underneath, and every campaign, flow and test is judged against those nine. George Kapernaros published it in Forbes in January 2026. Every YOCTO account runs on it.
How much do Underground Ecom alternatives cost?
None of the four agencies on this page publishes a rate card; every retainer is scoped custom. The useful comparison: ask each shortlisted agency to quote the same 90-day deliverables against the same baseline. Scoped quotes tell you more than list prices that don’t exist.
Can you switch Klaviyo agencies mid-contract?
Usually, yes. Most agency agreements run on 30-to-90-day notice periods, not annual locks. Check your notice terms, confirm you hold admin ownership of your Klaviyo account and sending domains, and time the handover outside your peak trading window. The five steps above cover the rest.
What happens when you contact YOCTO?
You start with a free diagnostic of your account against your own 90-day baseline. We then propose the system we’d build and the numbers it should move. If the diagnostic shows your current agency is doing the job, it says so, and you’ve spent an hour instead of a year on the wrong retainer.