Mailprompt vs Klaviyo: two ways to pay for email

What this page covers

This comparison is part of the Mailprompt comparisons set. It looks at one question: how does each product decide what to charge, and what does that choice reward? It is not a feature-by-feature scorecard, and it does not claim that one product is better for every store.

Two billing models in one sentence

Klaviyo's help center documents a plan built around active profiles. Mailprompt's plan is built around emails sent per month. The first model grows with the list; the second grows with the sending.

That difference sounds small until you map it onto a real store. A store with a large list and a careful sending cadence may look expensive under a contact-based model and modest under a send-based one. A store with a small list and a very high send frequency may see the opposite. Neither model is inherently fair; they charge for different resources.

What Klaviyo documents

Klaviyo's billing article says the Profile and Email plan must cover the number of active profiles at the end of the billing cycle. If the account has more active profiles than the plan allows, Klaviyo says it automatically upgrades the account to a profile-compliant plan at the end of the cycle.

The same article defines an active profile as any profile, regardless of consent status, that can be emailed through Klaviyo. That definition matters more than the headline number. A profile that cannot be emailed is treated differently from one that can, and consent status alone is not the whole test.

The practical consequence is that list hygiene has a billing effect. Removing profiles you cannot or should not email can reduce the count. Keeping a large, stale database because “we might use it later” has a cost even before the next campaign.

What Mailprompt does

Mailprompt charges by emails sent per month. The contact list is not the billing unit. A profile that receives nothing does not change the bill, and a campaign that goes to a small segment does not cost the same as a campaign that goes to the whole list.

The model is paired with a human approval gate. Every marketing send waits for a person to approve the current version, whether the draft came from the chat, the API or a connected client. The approval is not an upsell or a separate compliance product; it is part of the send path.

Mailprompt also reports revenue on a click-based, five-day, last-click model. Opens are shown but do not earn revenue credit. That is a reporting choice, not a billing one, but it belongs in the same conversation because it changes which emails look successful.

What each model rewards

A contact-based model rewards a clean list and a deliberate sending cadence. Every profile that can be emailed has a carrying cost, so the operator has a reason to ask whether a profile belongs. The model is easy to forecast when the list is stable, and it can become uncomfortable when the list grows faster than revenue.

A send-based model rewards relevance and segmentation. Sending more often costs more, so the operator has a reason to ask whether a campaign or a flow email has earned its place. The model is easy to forecast when the sending plan is stable, and it can become uncomfortable when a store sends a very high volume to a small list.

Neither incentive is a moral position. They are different ways of asking the customer to pay for the resource the vendor spends money on. The useful question is which resource your store actually consumes.

The switching question

A migration is not a pricing decision alone. Templates, segments, flows, historical reporting and the team's habits all move with the account. A store that has spent years tuning Klaviyo may find that the cost of a move is larger than the difference in the bill.

This page does not promise an importer. Importers are only credible after they have been tested against real exports, and an untested importer can lose segments, consent state or suppression history. If you migrate, plan it as a rebuild with a parallel run, not as a button.

The safer comparison is a trial on your own data. Recreate one flow, send it to a small segment, approve it through the new workflow and compare the click and order numbers with the same period in the old tool. A pricing model is easy to describe; a working flow is the thing you actually run.

Who each product fits

Klaviyo is a reasonable fit for a store that already has a mature Klaviyo setup, a stable active-profile count and a team that knows the interface. The billing model is documented and the platform is established. A move needs a reason beyond curiosity.

Mailprompt is aimed at stores that want to describe a flow in chat, keep a human approval on every marketing send and stop treating the contact list as the billable unit. It is also aimed at teams that want the product to explain its assumptions rather than hiding them in a builder.

If your list is large but your sending is selective, compare the two models with your own numbers. The current plans and allowances are on the pricing page. If your list is small and your sending is heavy, run the same comparison in the other direction. The answer should come from your sending pattern, not from a generic “cheaper” claim.

Related reading

• Mailprompt vs Mailchimp looks at a different contact-based model.
• AI flows by chat explains how a draft is produced.
• Revenue per email explains the attribution model.