About | NELVIO

Who we are

We live inside Klaviyo, so you don't have to.

NELVIO was founded on a simple idea: most brands are sitting on an email list that's quietly losing them money. Bad timing, weak copy, broken flows, lazy segmentation. Every unopened email is a customer drifting away.

We do one thing, and we do it properly. Email marketing in Klaviyo. No bloated retainers covering ten different channels. No junior account managers learning on your account. Just a focused, senior team that knows the platform inside out.

We've spent thousands of hours building flows, writing subject lines, A/B testing send times, fixing deliverability, and obsessing over every line of code in every email template. It shows in the numbers.

Email letters and envelopes, the craft we obsess over

"If your open rate looks fine but your revenue's flat, your email program is broken. We fix that."

The NELVIO philosophy

/ Who we work with

Built for some, not for everyone.

We're selective about clients so we can do our best work. Here's the honest filter.

+ Built for

DTC brands on Shopify with active paying customers
1,000+ email subscribers (or about to be)
On Klaviyo already, or ready to migrate
Treat email as a real revenue channel
Want a long-term partner, not a one-off sender
OK being told the truth about their numbers

− Not for

Pre-revenue startups still finding product–market fit
"Just send the emails" with no strategy attached
"Set and forget" mindsets — flows need attention
SMS-only programs (we focus on email)
B2B SaaS — we specialise in DTC ecommerce
Hourly contracts — we work on monthly retainers

Our expertise

What we actually know how to do.

Email looks simple on the surface. The difference between a £5k month and a £60k month is everything that happens underneath.

01 · Klaviyo, top to bottom

Flow builder, segmentation, signal-based triggers, conditional splits, dynamic blocks, predictive analytics, custom properties, webhook integrations, deliverability monitoring. We've used every corner of the platform.

02 · Copy that converts

Subject lines, preview text, headline hierarchy, scannable body copy, CTAs that don't feel like CTAs. Email copy is its own discipline. It isn't blog writing, isn't ad copy, isn't a product description. We treat it that way.

03 · Deliverability obsession

SPF, DKIM, DMARC, dedicated IPs, sender reputation, warm-ups, list hygiene, engagement-based suppression. If your emails are landing in Promotions or Spam, no amount of clever copy will save you. We make sure they land in the inbox.

04 · Segmentation strategy

VIPs, lapsed buyers, browse-abandoners, post-first-purchase, subscription churn-risk, channel preferences. The bigger your list grows, the more your revenue depends on talking to the right people, not all the people.

05 · Design that doesn't break

Mobile-first templates, dark mode handling, fallback fonts, render-tested across Gmail, Apple Mail, Outlook, and every major client. No more emails that look beautiful on your screen and broken on your customer's phone.

06 · Reporting that means something

We don't report on opens (they lie now). We report on revenue per email, revenue per subscriber, flow conversion, list growth, churn, and the metrics that actually predict your next quarter.

/ What we believe

A few principles we don't compromise on.

The kind of opinions you only get from doing this work every day for years.

/ Principle 01

Revenue, not opens.

Open rate is a vanity metric in 2026. We report on attributed revenue per email, per subscriber, per flow. The numbers that actually pay your team.

/ Principle 02

Send less, but better.

We don't believe in shipping seven emails a week to hit volume targets. We send fewer, sharper sends to the right segments. Your list (and your unsubscribe rate) will thank you.

/ Principle 03

Flows compound.

The flows you build today earn revenue every day for years. We invest there first, then layer campaigns on top. Compounding beats sprinting every time.

/ Principle 04

One tool, mastered.

We could be a multi-platform agency dabbling in five tools. Instead we're deep in Klaviyo. Mastery beats coverage every time, especially in email.

/ Principle 05

Truth over comfort.

If your list is too small to retainer, we'll tell you. If your audit shows the program is salvageable in-house, we'll say that too. The trust is worth more than the gig.

/ Principle 06

Senior people, always.

The person doing your audit is the person managing your account. No junior account managers learning on your data, no white-labelled outsourced work.

Email, obsessively done.