If you sell products online and you are choosing today, pick Klaviyo. That is the same answer every comparison post gives, and it is right for a fairly boring reason: Klaviyo is built around your store's event stream, Mailchimp is built around a contact list you send to. Most of the posts saying so are paid per signup to say it, so here is the part they leave out.
What is the actual difference between the two?
Segmentation, and not in the way the feature tables mean it.
In Mailchimp the unit is an audience: a list you add people to and clean occasionally. Segments sit on top as saved filters, and the cheaper plans give you a handful. In Klaviyo the unit is a profile with everything that person has ever done attached to it, and a segment is a live query over that history. Nobody joins a Klaviyo segment. They match it this morning and stop matching it tonight, without anyone touching anything.
That reads like a distinction for engineers. It is the whole thing. A flow pointed at a live query keeps finding new people forever. A flow pointed at a frozen list mails the same pool until the pool is exhausted or annoyed.
We took over an account where that had been running for months. The re-engagement flows were aimed at segments that could not grow, and over the period we measured they produced 64,342 sends, 635 unsubscribes and €0. It was a sports-supplement brand with a healthy list and a competent operator. The flows were not underperforming. They were doing precisely what they had been built to do, to an audience that had already heard it twice.
Does moving to Klaviyo make your email make more money?
Not on its own, and this is the question worth sitting with before anyone pays a migration fee.
Klaviyo will run the same three campaigns a week to the same static list you were mailing before, and charge you more for the privilege. What moves revenue is the flows and the segments underneath them, and that work is roughly the same work on either platform. We went through where the money actually sits in more detail, and the short version is that it concentrates in a small number of automations that run without you.
If you want the order to build those in, start with the five segments worth having before any clever ones.
What does each one actually bill you for?
Different things, and the difference quietly shapes how you behave.
Mailchimp prices on contacts and caps sends at a multiple of that number, ten to fifteen times your contact count depending on tier. Automation depth and A/B testing are gated by plan, so you meet the paywall when you get good rather than when you get big.
Klaviyo prices on active profiles, which is a narrower and more slippery number than everyone sitting in the account. It has a trap of its own, and we wrote that one up separately.
The practical effect is that Mailchimp punishes sending and Klaviyo punishes hoarding. A list full of people who have not opened anything in a year is expensive to keep in Klaviyo, which is usually an argument for cleaning it rather than for staying put. If cleaning it leaves you with almost nobody, that is its own diagnosis.
When is Mailchimp still the right answer?
When you are not really an ecommerce store. A newsletter, or a service business sending a monthly update: the behavioural data that makes Klaviyo worth its price does not exist yet, and you would be paying for an engine with nothing to run on. Mailchimp is also easier for one person sending one campaign a month who wants it to look fine and be done by lunch.
The switch earns its cost once there is enough customer behaviour to act on. For a store doing real order volume, that is already true.
The order to do this in
If you are on Mailchimp and email is flat, the platform is the last thing to change rather than the first. Work out which flows exist, what each one is aimed at, and whether that target can grow. Do that honestly and you will often find the flat number has nothing to do with the logo on the invoice.
Then migrate, if you still want to. Moving a dead list gives you a dead list with better analytics and a larger bill, and we would rather you knew that before the quote than after.
