GUIDE
Pay per email or pay per contact: which billing model wins
Two billing units split the market. Brevo charges by emails sent and keeps contacts unlimited, so cadence is the bill. MailerLite and Sender charge by contacts, so list size is the bill and sending is effectively free up to a cap. Pay-per-email wins on a big list you mail rarely; pay-per-contact wins on an engaged list you mail often. Cadence is the deciding variable.
Two units, two meters
Every platform here bills on one of two units. Pay-per-contact platforms, MailerLite, Sender and most of the field, meter the size of your list and let you send within a generous multiple of it. Pay-per-email platforms, Brevo being the clear example, keep contacts unlimited and meter the sends. The unit is not a detail, it is the whole cost curve. The same list and the same campaigns produce very different bills depending on which meter is running, so the first decision is not which brand but which unit fits how you actually mail.
When pay-per-email wins
Brevo (free plan, paid from $9/mo) shines when contacts are many and sends are few. A large but mostly dormant list, tens of thousands of names you email once a month or only on triggers, costs little because you are billed on the handful of sends, not the pile of contacts. Add transactional email in the same account and it suits stores and apps that send receipts and the odd campaign. The model turns punishing the moment cadence climbs, because every extra send is metered, so it rewards restraint.
When pay-per-contact wins
MailerLite (free plan, paid from $12/mo) and Sender (free plan, paid from $9/mo) win the opposite case: a smaller, engaged list you mail often. Because sending is free up to a multiple of your subscriber tier, a weekly newsletter, a welcome sequence and the odd resend cost the same as sending nothing extra. You pay for the list, not the frequency, so high cadence is where this model pulls clearly ahead. The ceiling only bites at very high volume, which is the signal to move up a plan rather than a reason to switch units.
Let cadence and the calculator decide
The crossover is set by cadence times list size, so read it at your real numbers rather than in the abstract. The cost calculator shows both units side by side, and the frequency and list size guide explains how the two axes interact. To see one contact bill against one email bill directly, the MailerLite versus Brevo comparison is the cleanest example of the trade.
Questions people also ask
Which model is cheaper overall?
Neither in general. Pay-per-email is cheaper for a large list mailed rarely; pay-per-contact is cheaper for an engaged list mailed often. Your cadence and list size decide, which is why the calculator compares both.
Does pay-per-contact really make sending free?
Up to a cap, yes. Platforms like MailerLite and Sender include a multiple of your subscriber count in monthly sends, so normal cadence costs nothing extra. Only very high volume pushes you to the next plan.
I have a huge dormant list. What fits?
Usually a pay-per-email platform like Brevo, since it keeps contacts unlimited and bills only the sends. Confirm it at your numbers, because a large list mailed frequently can flip back to pay-per-contact.