Arena: Market Conditions Before Klaviyo
Online merchants · 2012 · United States first, then worldwide
Disconnected workflowsBarriers to participation
In 2012 an online merchant kept orders in its store platform and sent newsletters through a separate email service. What a shopper had browsed, bought and opened sat in different tools, so the email list knew addresses but not customers K2. Large retailers paid analytics firms to work out who their customers were, exported the answers to spreadsheets and loaded them back into email by hand K3. A smaller store had no such budget: a segment of repeat buyers, or a message sent when a cart was abandoned, meant exports, manual rules or custom engineering, and the tools that could do more demanded technical staff the store did not have K2.
How each step happened
Step 1 of 5 · 2012–14
A commerce data store that sends email
Klaviyo's innovation was to build the store's customer database first and make email one of its outputs. Andrew Bialecki and Ed Hallen had worked at a company selling data analytics to Fortune 500 retailers, and saw those retailers holding loyalty and purchase data they did not use to personalize marketing K3. Bialecki says the idea was one place to store all of a business's customer data, connected to every point where the business met its customers, 'starting with email' K3. The first product in 2012 was a custom store for ecommerce events and customer profiles; email came about two years later, when customers asked for it KLX-5.
Mailchimp started from the other end: an email tool whose unit was a list of subscribers, with store data brought in through integrations KLX-7. Because Klaviyo's data layer came first, every message could draw on a shopper's whole history of orders and visits. The S-1 calls that layer the foundation on which all of Klaviyo's functionality was built K2. A list-based tool could add store data, but only by importing it into a model designed for addresses.
Rivals Mailchimp organized contacts into audiences with tags and basic segments, and priced by audience contact KLX-7 KLX-3. It was the familiar email tool for small businesses of every kind K2.
Novel ArchitectureFounder Domain Expertise
Step 2 of 5 · 2012–19
Ecommerce specialization: revenue the merchant can see
Klaviyo first pitched to other software startups, then chose online retail K3. Bialecki gives the reason: software buyers weigh cost against benefit, and in retail 'the loops are much faster', so a merchant can see which purchases followed a message and the value of personalization is plain K3. Hallen found that ecommerce operators had problems that had gone unsolved for years, and the founders had spent their careers joining data sources together KLX-5.
The specialization shaped the product. Triggers and segments ran on purchases and browsing, not on a separate list of addresses K1 K3. Today a merchant can segment on any event or property, including a predicted next order date or lifetime value KLX-7. Klaviyo also reports the revenue its messages produce, counting orders placed within a set window after an email or text K2. That made the product easy to justify, and it made the next step natural: Shopify's merchants were exactly this customer.
Rivals In May 2019 Mailchimp repositioned itself as an all-in-one marketing platform for small businesses, adding websites, ad retargeting, postcards and social media KLX-3. In April 2021 it launched Websites & Commerce so users could build their own storefronts KLX-2.
Vertical SpecializationPersonalization
Step 3 of 5 · 2012–22
Shopify's preferred marketing partner
Klaviyo's first ecommerce customer was a friend's Shopify store, and Bialecki chose Shopify for its well-documented APIs and a nearly self-serve app store K3. Klaviyo listed its integration there and, in his words, rode part of Shopify's growth through 2012, 2013 and 2014 K3. Installing from the app store synchronized store events into Klaviyo's data layer with little setup K2.
The decisive moment came in March 2019. Shopify's new partner terms required marketing apps to synchronize customer names, contact details and marketing consent back to merchants' stores KLX-1. Mailchimp refused, saying the data was not its to share, and pulled its app, though one estimate had at least 30% of Shopify merchants using it KLX-1. Shopify recommended Klaviyo as the alternative, and Klaviyo said 10,000 former Mailchimp customers moved to it over the next two years KLX-2.
The partnership deepened. In July 2022 Shopify bought shares in Klaviyo and made it the recommended email product for Shopify Plus, its tier for larger merchants K2. By the end of 2022, 77.5% of Klaviyo's annual recurring revenue (ARR) came from customers who also used Shopify, though only 10.6% of new ARR came through the app store; most arrived through word of mouth and agencies K2.
Rivals Mailchimp's Shopify merchants relied on a third-party connector, ShopSync, for two years; Mailchimp bought it and returned in October 2021 KLX-2. Its partnerships head said the two companies had been fundamentally misaligned on data KLX-2.
Distribution Partnerships
Step 4 of 5 · 2019–25
Accounts grow with the store: usage pricing plus SMS on the same profiles
Klaviyo's plans are tiered by the number of active consumer profiles stored plus the emails and text messages sent, so a growing store pays more without a new purchase decision K2. SMS, added by 2020, reused the same profiles, events and flows, the automated message sequences a merchant builds once K2 K1. A store that switched on texting needed no new tool. Net revenue retention, what a year-old group of customers pays now against a year earlier, was 119% at the end of 2022, and the S-1 credits expanded usage and SMS K2. More than 5,000 agencies referred leads in 2022 K2.
Revenue rose from $472.7 million in 2022 to $1,234.0 million in 2025, when Klaviyo served more than 193,000 customers and net revenue retention was 110% K2 K1. In 2025 it presented the product as a customer relationship system for consumer businesses, adding customer-service tools on the same profiles K1.
Rivals Mailchimp's 2019 pricing billed for a whole audience, including unsubscribed contacts unless the customer archived them KLX-3. Its breadth paid off: with 800,000 paid customers across all kinds of small businesses, it agreed to sell to Intuit for about $12 billion in September 2021 KLX-4.
Usage-Based PricingPlatformization
Step 5 of 5 · 2019–26
Switching costs
The data store from step 1 is what makes Klaviyo costly to leave. It holds the entire history of profile and event data for each shopper K2. Klaviyo's own exit guide lets a departing merchant export lists, segments, templates and reports, and warns that deleted flows cannot be recovered; flow logic is not among the exports KLX-6. Leaving means rebuilding every automation and signup form in the new tool, and an agency guide describes the same rebuild for stores moving from Mailchimp to Klaviyo KLX-7.
Each year a store stays adds orders and visits to its profiles and more flows tuned to them, so the rebuild grows with the relationship. Gross revenue retention, which counts only revenue lost from departing customers, was 88% in mid-2023 K2.
Rivals Mailchimp publishes a guide for moving from Klaviyo and a named retailer that made the move in 2025 R10 R6. Klaviyo publishes its own guide for merchants leaving Mailchimp R8.
Switching costsData Gravity