It is notoriously difficult to obtain reliable customer data for email service providers.
In a recent LinkedIn post, which got over 5,000 impressions, I tried to come up with a ranking based on Datanyze data.
However, the data felt a bit…wonky.
For example, who has ever heard of AcyMailing? And why are Brevo and ActiveCampaign missing from this list?
To create a more realistic ranking, I tried to find the data the ESPs publish themselves about their user numbers. Fortunately, almost all the SMB-focussed email service providers publish some sort of user data.
The 17 Most Popular ESPs
Based on the latest self-reported data, here's a breakdown of the user numbers and (hypothetical) market share for the top ESPs:
| ESP | Number of Users | Market Share (Hypothetical) | Country | Source | Comment |
|---|---|---|---|---|---|
| Mailchimp | 11,000,000 | 70.86% | USA | Mailchimp website | “11 million businesses use Mailchimp.” |
| MailerLite | 658,530 | 4.24% | USA / Lithuania | MailerLite website | “Join 658,530 creators and businesses using MailerLite.” |
| Constant Contact | 650,000 | 4.19% | USA | Constant Contact press release | “The company helps more than 650,000 customers.” |
| Brevo | 500,000 | 3.22% | France | Brevo website | “500K Customers globally” |
| Benchmark | 500,000 | 3.22% | USA | Benchmark Email website | “Over 500,000 users“ |
| GetResponse | 400,000 | 2.58% | Poland | GetResponse website | “400,000+ customers worldwide” |
| CleverReach | 370,000 | 2.38% | Germany | CleverReach website | “370,000 customers worldwide” |
| Campaign Monitor | 250,000 | 1.61% | Australia | Campaign Monitor website | “250,000 companies worldwide love Campaign Monitor.” |
| Hubspot | 216,000 | 1.39% | USA | HubSpot Newsroom | “Over 216,000 customers” (Includes non email marketing customers) |
| Keap | 205,600 | 1.32% | USA | Keap website | “205.6 K Users” (31.5K customers) |
| ActiveCampaign | 150,000 | 0.93% | USA | ActiveCampaign website | “150,000+ small businesses around the globe use ActiveCampaign.” |
| Klaviyo | 143,000 | 0.92% | USA | Klaviyo investor report | “Over 143,000 customers are using Klaviyo.” |
| Omnisend | 100,000 | 0.64% | Lithuania | Omnisend website | “100K+ happy customers worldwide” |
| AWeber | 100,000 | 0.64% | USA | AWeber website | “AWeber is an email marketing service provider helping over 100,000 customers.” |
| Campaigner | 100,000 | 0.64% | USA | Campaigner website | “over 100,000 businesses“ |
| Email Octopus | 83,000 | 0.54% | UK | Email Octopus website | “We've helped over 84,000 organisations.” |
| Kit | 56,513 | 0.36% | USA | Kit Baremetrics page | Baremetrics stats (real customers) |
| Mailjet | 40,000 | 0.26% | France | Mailjet website | “With over 40,000 customers in 150 countries” |
Data originally collected in June 2024.
Similar to the Datanyze data I used in my LinkedIn post, Mailchimp is absolutely dominating the email marketing market by their number of users. They were one of the first companies to introduce a freemium plan, and that also seems to be the reason for their huge popularity. However, it's unclear how many of them actually pay.
MailerLite is another ESP that offers a (generous) free plan. The number we were able to gather refers to users rather than customers.
Constant Contact and Brevo are the first ones that talk about customers. If they really have more than half a million customers, that's enormous.
A bit of a surprise is CleverReach, which isn't widely known internationally. They are likely the biggest ESP in German-speaking countries (Germany, Austria and Switzerland) and claim to have almost 400K customers, which is almost as big as GetResponse.
More expensive ESPs like ActiveCampaign, Klaviyo and Keap don't have the same user numbers as the more popular ESPs; however, we can assume that their margins are considerably higher.
Limitations of the data
It's important to note that the data comes from the websites of the ESPs themselves. While this is the best data available, it should be taken with a grain of salt. The companies use different terms to describe their users. Some call it “users,” others “customers,” or “companies”, which can sometimes be misleading. A “user” or a “company” doesn't always pay for the service if there's a free tier available. A customer, on the other hand, indicates that money is being exchanged.
The best data, without a doubt, comes from Kit. Their metrics are openly available in a Baremetrics dashboard along with their revenue and many other interesting business figures.
Unfortunately, we weren't able to find good data for Moosend, Drip or SendPulse. Moosend says, “Moosend is used by thousands of businesses”. We couldn't find any data for Drip. And SendPulse says this: “SendPulse reached 1 million 934 thousand registered users”, which seems unrealistically high, given their relatively small brand. Neither Google search volumes (based on Ahrefs) nor other data sources (e.g. Datanyze) indicate a high popularity that is that high.
The market share number you find in the table is hypothetical. It's based on user/customer numbers and doesn't reflect a monetary value. If sales were taken into account, players like Salesforce, Listrak or SAP emarsys might play a much bigger role.
Conclusion
Based on all the data sources available, using the ESP's self-reported data seems most reliable.
Mailchimp continues to dominate the market with a significant lead, boasting over 11 million users. Other providers like MailerLite, Constant Contact, Brevo, and Benchmark also have substantial user bases, but they lag behind Mailchimp's impressive numbers.
When choosing an ESP, it's essential to consider not just the number of users but also the specific features and capabilities that meet your business needs. That's where we come in:
> Compare the best email marketing services
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09 Jul 2024 – Campaigner added, other small corrections
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This article has been written and researched following our EmailTooltester methodology.
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