Per contact vs per send

A per contact vendor charges the same whether you send once a month or twenty times, up to the send allowance attached to the tier. A per send vendor charges by volume, so a 50,000 contact list that mails once a quarter costs almost nothing and a 2,000 contact list that mails daily costs a lot.

Placing Brevo at a contact breakpoint therefore requires a stated send frequency. SideBySend assumes 4 sends per contact per month, which is one weekly campaign and nothing else. Add a welcome sequence, a re engagement flow or transactional mail and the real band is higher than the table says.

This is the single largest assumption in the dataset, which is why it lives on its own page rather than in a footnote.

At 500 contacts, Brevo Standard is $18 and Mailchimp Essentials is $13, so the contact billed vendor wins on price at the very bottom.

At 25,000 contacts it flips hard. Brevo Standard is $139 against Mailchimp Essentials at $270, because a weekly send to 25,000 contacts is only 100,000 emails a month and Brevo prices that band cheaply.

Send more often and that advantage disappears. Three sends a week to 25,000 contacts is 300,000 emails a month, which pushes Brevo Standard up to the 350,000 send band, well above the 100,000 send band a weekly list of that size needs.

Even among the per contact vendors the definition moves. ActiveCampaign bills accounts opened on or after 3 November 2025 for unsubscribed, bounced and unconfirmed contacts. Mailchimp counts unsubscribed contacts until they are archived. MailerLite and Kit count only active or confirmed subscribers. beehiiv drops unsubscribes from the billable count but leaves suppressed addresses inside it.

So two vendors quoting the same price for 10,000 contacts can produce different bills for the same list, because they disagree on what 10,000 means. The full record, with the parts no vendor page answers, is in who bills unsubscribed contacts.