Klaviyo Agency
A Klaviyo Agency Built for Retention, Lifecycle, and Real Growth.
Most brands “have Klaviyo.” Very few have a lifecycle system. We build and operate Klaviyo as the engine of retention, expansion, and long-term revenue growth for $3M-$100M+ DTC and subscription brands.
The email team behind multiple INC #1 fastest-growing brands
The Problem
Most Brands “Have Klaviyo.” That's the Problem.
Flows exist, but they're outdated, under-tested, or sequenced incorrectly. Campaigns go out, but they're repetitive, predictable, and easy to ignore. Metrics look fine. Revenue plateaus anyway.
Klaviyo isn't a tool. It's a lifecycle engine. That's how we treat it.
When Klaviyo Is Run Correctly
Klaviyo Is the Engine of Lifecycle Growth.
It does more than “send emails.” It:
How We Run Klaviyo
Four Phases. One Lifecycle Engine.
01
Research & Insight
We start with customer truth, not assumptions. Reviews, surveys, on-site behavior, historical campaigns, and lifecycle data inform everything that follows.
02
Flows & Lifecycle Systems
We build systems, not templates. From welcome to post-purchase to re-engagement, every flow has a job and a measurable outcome.
03
Creative & Messaging
Designed emails when they matter. Plain-text when they perform. We avoid banner blindness by mixing formats, voices, and intent.
04
Optimization & Measurement
We optimize for business impact. Retention, LTV expansion, reorder rates, and revenue increases. Not vanity dashboards.
Why This Feels Different
Six Things Most Klaviyo Agencies Don't Do.
Specialists at every phase
Strategy, copy, design, dev, QA, PMs. No generalists doing everything 'fine.'
Lifecycle innovations others copied
Including in-cycle upselling for subscription brands.
Format flexibility
Designed campaigns and plain-text sends that actually get read.
Results that compound
Not short-term spikes. We build for retention math, not vanity metrics.
Proven partnerships
Average email client relationship of over 3.5 years.
Your team, expanded
We operate as an extension of your team, not a vendor.
What Clients Say After Switching
“Best around for email.”
They are the BEST around when it comes to email strategy, design & execution. They are incredibly responsive & always go the extra mile. Sweat Pants Agency feels like an extension of our team.
Melissa Ehrlich
VP of Marketing, Hustle Butter
“Transformative for our brand.”
Partnering with Sweat Pants Agency has been transformative for Completing The Puzzle. Their strategic approach to email marketing has significantly increased our customer retention rates and boosted our revenue beyond expectations.
Brian Thomas
Co-Founder, Completing The Puzzle
“Their email design team is fantastic.”
I really enjoy working with the Sweatpants team. Their email design team is fantastic. They come up with fun, engaging designs that have drastically improved our email performance.
Jennifer Rea
VP of Marketing, Crafters Box
Trusted by Category-Defining Brands
Fit Check
We're Selective. You Should Be Too.
Good fit if...
Probably not a fit if...
What You're Probably Wondering
Klaviyo is the most powerful ESP for DTC and ecommerce, but most brands use a fraction of what it can do. The brands that get real revenue out of Klaviyo treat it as a lifecycle engine — segmentation, predictive analytics, behavior-triggered flows, and custom campaigns that compound. That requires senior expertise, not just an account login.
Get a Free Klaviyo Audit
Our team of experts live, breathe, and geek out on Klaviyo so you don't have to.
What's in the audit
