Why Brands Switch to Klaviyo From Mailchimp (And What Actually Changes)

Direct answer: Brands switch to Klaviyo from Mailchimp when their email program stops being a newsletter and starts being a revenue channel. The specific triggers are billing on unsubscribed and non-subscribed contacts, automation that cannot branch on order history or product-level behavior, and attribution that will not stand up in a board meeting. Sticky Digital recommends making the move only when you have a written plan to rebuild your core flows inside Klaviyo, because a straight data import into a platform you use the same way you used the old one produces roughly the same results at a higher price. For Shopify brands doing real repeat volume, the switch typically pays for itself through flow revenue, not through campaign sends.

Sticky Digital's perspective on why brands switch to Klaviyo from Mailchimp

We only do retention. Email, SMS, loyalty, subscription. That means we inherit a lot of Mailchimp accounts, and we see the same sequence of events over and over.

A brand launches on Shopify. Mailchimp is familiar, cheap at the start, and does what a newsletter needs to do. The list grows. Someone builds an abandoned cart email. Revenue from email sits somewhere around eight to twelve percent of store revenue and stays there. Then the bill goes up, nobody can explain why, and a founder asks the obvious question: are we on the wrong tool?

Usually the answer is yes. But the reason it is yes has almost nothing to do with the feature comparison charts. It is that the brand has quietly become an ecommerce business with purchase cycles, replenishment windows, VIP tiers, and lapsing customers, and it is still running on software that thinks of those people as rows on a list. Across the accounts we manage in beauty, wellness, apparel, and home, clients attribute roughly 35 to 50 percent of total store revenue to email within six months of a properly built program. You cannot get there on infrastructure that cannot tell you what someone bought and when they are likely to buy again.

One disclosure before we go further, because it affects how you should read the rest of this: Sticky Digital is a Klaviyo Platinum Partner. We have a commercial relationship with one of the two platforms in this article. We are going to tell you where Mailchimp is genuinely the better answer anyway, and we are going to tell you the part of the Klaviyo pitch we think is oversold.

The four walls brands hit in Mailchimp

You are billed for people you are not allowed to email

This is the one that produces the most phone calls. Since April 2024, Mailchimp counts subscribed, unsubscribed, and non-subscribed contacts toward your plan limit and your price. Unsubscribed contacts keep costing money until someone logs in and manually archives them. Most brands never do, because nobody told them it was a job.

The result is a bill that climbs on its own. Your list grows whether or not your results do, and a portion of that growth is people who have already told you to stop emailing them. In January 2026 Mailchimp also cut its free plan from 500 contacts and 1,000 monthly sends to 250 contacts and 500 sends, which pushed a lot of small merchants into paid tiers earlier than they had planned.

Klaviyo bills on active profiles, which excludes unsubscribed and suppressed contacts. The meter still rewards list growth with a higher bill, so this is not a charity. The difference is that suppression is a lever you can actually pull. At 10,000 contacts Mailchimp Premium runs about $350 per month. At 10,000 active profiles the Klaviyo email plan runs about $150. At 5,000, it is roughly $100 on Mailchimp Standard against roughly $100 on Klaviyo. The pricing gap is not the argument people think it is, and at small list sizes Mailchimp frequently wins on cost.

The automation is built for lists, not for purchase behavior

Mailchimp's multi-step automation lives behind the Standard plan and upward. It works. What it struggles with is the logic an ecommerce program actually needs: branch on whether this is a first or third order, wait until 47 days after purchase of a specific SKU, hold the message if the customer has an open subscription, exclude anyone who has a shipment in transit.

That is not a feature gap you notice when you have three flows. It becomes the whole problem when you have fourteen, and they need to know about each other.

Tags are not segmentation

Mailchimp organizes people with tags and groups. Klaviyo organizes them with event data that updates continuously. The practical difference: a Mailchimp tag records that something was true at the moment it was applied, and a Klaviyo segment recalculates whether it is still true right now.

A customer who was a VIP in March and has not ordered since is still tagged VIP in Mailchimp. In Klaviyo they have already moved into a lapsing segment and are getting a different message. Multiply that across a list of 80,000 and the cost of static targeting shows up as unsubscribes and dead sends.

Attribution you cannot defend

When a founder asks what email contributed last month, the answer has to survive scrutiny. Klaviyo's Shopify integration syncs order and browsing data natively, and revenue attribution is built into the flow and campaign reporting. Shopify holds an ownership stake in Klaviyo of roughly 11 percent and lists it as the recommended email platform for Shopify Plus, which is worth knowing as context for why the integration is as deep as it is. About 78 percent of Klaviyo's revenue is tied to the Shopify ecosystem.

Mailchimp can report on ecommerce revenue. It reports on it as an integration reporting on an external store, not as a system that holds the store's data model. That distinction is invisible until you need to prove something.

What actually changes after the switch, and what does not

Here is the part most migration content skips.

What changes: the ceiling. You can now build flows that branch on order history, run replenishment timing off actual product cycles, suppress across email and SMS from one place, and report revenue by flow and by message. Brands that were running four flows commonly end up running fourteen to eighteen, and the newly possible ones (post-purchase education, replenishment, browse abandonment, winback tiered by lifetime value) are where the incremental revenue sits.

What does not change: your creative, your offer strategy, your send discipline, and your list hygiene. Deliverability is not a property of the platform. It is a property of who you send to, how often, and how they respond. A brand that emails a cold list four times a week will get the same spam folder placement in Klaviyo that it earned in Mailchimp, and it will pay more for the privilege.

If you are unhappy with your email revenue and your current program is four flows and a weekly newsletter, the platform is not your binding constraint. The program is. We have told brands to stay on Mailchimp and fix the program first, and some of them did exactly that and came back to us a year later with a real reason to move.

Why lift-and-shift migrations fail

The failure mode we see most often is not a botched data export. It is a competent data export followed by nothing.

A brand exports the CSV, imports it into Klaviyo, recreates the same four flows with the same copy, points the domain, and sends. Three weeks later revenue is flat or slightly down, the bill is higher, and someone concludes Klaviyo is overrated. What actually happened is that they paid to move a newsletter program into a lifecycle platform and then ran it as a newsletter program.

Three specific things go wrong inside that pattern.

Consent and suppression data gets left behind. Exporting email addresses is easy. Exporting subscription method, opt-in timestamp, unsubscribe history, and bounce history is the part people skip, and it is the part that protects you. Klaviyo's own migration guidance is explicit that brands coming from Mailchimp should suppress contacts carrying a one-star rating before import, because sending to them damages deliverability from the first campaign.

Sender reputation is assumed to travel. It partially does and partially does not. Reputation attaches to the sending domain and the IP, so if you keep the same From domain and repoint authentication records, a meaningful amount of your history carries over. If you stand up a brand new subdomain, you are starting from zero and mailbox providers will treat you accordingly. Either way a staged ramp over two to three weeks, starting with your most engaged segment, is the difference between a clean cutover and a month of explaining a deliverability dip that looks like an audience problem.

Static tags get imported and trusted. Mailchimp tags and Klaviyo profile properties are not equivalent. Imported tags arrive frozen. If your new segmentation is built on them rather than on Klaviyo's behavioral events, you have rebuilt the old system inside the new one. We see more of these than any other migration error, and they are the hardest to spot because everything appears to be working. You can read more of how we break down retention failures on the Sticky Digital blog.

How Sticky Digital runs a Mailchimp to Klaviyo migration

The order matters more than the checklist. Ours runs like this.

• Baseline first. We record flow revenue, campaign revenue, revenue per recipient, unsubscribe rate, and list size in Mailchimp before anything moves. Without a baseline you cannot prove the migration worked, and you will spend the next quarter arguing about it.
• Migrate consent, not just contacts. Opt-in method, timestamp, unsubscribes, bounces, and Mailchimp's own engagement ratings all come across, and the low-rating contacts get suppressed on arrival rather than emailed once and suppressed after.
• Rebuild the revenue flows before cutover, not after. Welcome, cart abandonment, and post-purchase are live and tested in Klaviyo before a single campaign sends from the new platform. Brands that cut over first and build second lose four to six weeks of flow revenue during the gap.
• Run both platforms in parallel. For lists above roughly 10,000, Mailchimp stays active while Klaviyo warms. There is no single moment where everything switches, which means there is no single moment where everything can break.
• Rebuild segments from event data. Every segment gets written against Klaviyo's behavioral events rather than imported tags, even when a tag exists that looks close enough.
• Compare against the baseline at 30, 60, and 90 days. Flow revenue as a share of total email revenue is the number we watch. If it is not climbing by day 60, the rebuild was incomplete, not the platform.

We do this across beauty, wellness, apparel, home, and pet brands, including accounts like Murad, Hanky Panky, Maison Miru, Hilma, and Pretty Litter. If you want the migration handled end to end rather than run internally, our team can scope it. The full range of what we cover sits on our retention services page.

When staying on Mailchimp is the right call

There are real cases, and pretending otherwise would make the rest of this article less useful.

Stay if your list is under about 2,500 contacts and your revenue per contact is low. The Klaviyo feature set you would be paying for does not activate at that scale, and the cost difference is money better spent on acquisition or product.

Stay if you are not on Shopify or another platform with a deep native Klaviyo integration. A large share of Klaviyo's advantage is the store data model. Without it you are buying a more expensive send button.

Stay if you send a genuine newsletter rather than an ecommerce program. Content businesses, nonprofits, and B2B lists with long unstructured cycles do not benefit much from purchase-behavior automation, because there is no purchase behavior to automate against.

Stay, for now, if you have nobody to rebuild the flows. A migration without an owner is a cost increase with extra steps. Fix that first, then move.

FAQ

Is Klaviyo more expensive than Mailchimp?

It depends on list size and list hygiene. At 5,000 contacts the two are close, with Mailchimp Standard around $100 per month and Klaviyo's email plan around $100. At 10,000 the picture flips in Klaviyo's favor, roughly $150 against $350 for Mailchimp Premium. The larger structural difference is that Mailchimp bills for unsubscribed and non-subscribed contacts until they are manually archived, while Klaviyo excludes suppressed profiles from the active profile count that drives the bill.

Will switching to Klaviyo hurt my email deliverability?

Temporarily, if the migration is rushed. Sender reputation attaches to the sending domain and IP, so keeping the same From domain and repointing authentication records carries much of your history forward. A new subdomain starts cold. Either way, ramping volume over two to three weeks beginning with the most engaged segment prevents the dip, and importing unsubscribe and bounce history prevents the worst of it by keeping bad addresses out of the first sends.

How long does a Mailchimp to Klaviyo migration take?

The technical portion, meaning the Shopify connection, contact import, and domain authentication, usually takes a few days and is mostly waiting on syncs. The full migration including flow rebuild, segment reconstruction, and a staged warmup runs three to six weeks for most brands. The variable is not the data. It is how many flows need to exist on the other side.

Does all of my Mailchimp data transfer to Klaviyo?

Contacts, merge fields, tags, unsubscribe records, bounce history, and recent engagement transfer. Campaign templates and historical campaign reporting largely do not, and tags arrive as static properties rather than live segments. Plan to export any historical reporting you need for benchmarking before you close the Mailchimp account, because it is not retrievable afterward.

Do I need an agency to migrate from Mailchimp to Klaviyo?

No. The migration itself is documented well enough that a capable in-house marketer can run it. The part that justifies outside help is the rebuild: deciding which flows should exist, writing the segment logic against event data instead of imported tags, and sequencing the warmup so revenue does not dip during cutover. If your team has that capacity, run it yourself.

Getting it done

Brands that want the migration and the flow rebuild handled end to end can start here. We will tell you if the switch is not the right move.

Article By: Mariel Kilroy, Co-Founder, Sticky Digital

Mariel Kilroy is the Co-Founder of Sticky Digital, a retention marketing agency specializing in email, SMS, loyalty, and subscription growth for DTC brands.