Companies Using Mailchimp

With 10+ years in web crawling and technographic data analysis, I've examined 526,676 active Mailchimp domains and enriched 328,239 of them with firmographic data (a 62.3% match rate) at TechnologyChecker.io. Mailchimp is still the most detected email platform on the web, but the shape of its base has changed and the churn corridors tell you where the pressure is. Here's what our data reveals for sales teams targeting this install base.

Growth Trajectory

In our long-run detection history Mailchimp peaked at 362,487 active domains in March 2025 and fell to 313,840 by July 2025, a 13.4% decline in four months that lines up with the post-Intuit pricing restructuring, particularly among users on formerly free or low-cost tiers. Our current crawl, which covers a wider slice of the web, now detects Mailchimp on 526,676 domains and the month-over-month move is flat (526,493 in July 2026, 526,676 in August). Those two figures are not like-for-like, because the set of domains we crawl turns over every month, with dead sites dropping out and newly discovered ones added, and our detection signals widen over time, so read the step across the chart's 2025-to-2026 gap as coverage, not growth.

The live churn signal is cleaner than any historical ratio: 31,680 domains have dropped Mailchimp since we began tracking it in March 2026. That is the pool actively in motion right now.

Sales Signal: Those 31,680 recent leavers are prime targets for competitive outreach. They've already decided to leave but may not have settled on a replacement yet. Time your outreach to the migration window, not after it closes.

"Mailchimp is not shrinking, it is leaking. Thirty-one thousand domains dropped it in five months while the total held flat, which means it is refilling the top of the funnel as fast as it loses the bottom. The businesses still on it aren't loyal, they're undecided. That's the most valuable audience in email marketing right now." - Mehmet Suleyman, CEO at TechnologyChecker.io

Customer Profile

86.3% of Mailchimp customers have 50 or fewer employees, with the 1-10 segment at 61.3%. This is a small-business platform through and through. The 2010s cohort (companies founded 2010-2019) dominates at 41.9%, meaning the typical Mailchimp user is a digital-native business roughly 7-16 years old. Only 0.3% of the user base qualifies as enterprise (5,001+ employees), but that fraction includes names like DHL Express, Honeywell, AstraZeneca, and Coca-Cola.

The enterprise detections tell a specific story. The University of California's is on health.universityofcalifornia.edu, Carrefour's on voyages.carrefour.fr, the City of New York's on access.nyc.gov. These are departmental or campaign-specific deployments, not company-wide email infrastructure. Large organizations use Mailchimp for specific marketing projects while running enterprise platforms like Marketo or Salesforce Marketing Cloud for their primary operations.

Sales Signal: The sweet spot for selling to the Mailchimp install base is companies with 11-200 employees (33.9% of all users). They're large enough to have budget but small enough that Mailchimp is their primary platform, not a departmental side tool. Pitch to the business owner or marketing manager directly. For the enterprise sliver, pitch a consolidation play: "You're already paying for Mailchimp on one microsite and [Enterprise Tool] company-wide. We can handle both."

Industry and Geographic Concentration

Retail leads at 6.98%, and adding Retail Apparel and Fashion (2.68%) puts consumer retail close to one in ten Mailchimp domains. Outside that, nothing reaches 3%. Mailchimp is the definition of a horizontal platform. Non-profits at 2.72% are the second-largest single segment, and Capterra reviewer data suggests they are disproportionately engaged: Non-Profit Organization Management accounts for 28% of Capterra reviewers despite being a fraction of detected installs.

Geographically, the US holds 34.9% and the UK adds 12.5%. English-speaking markets together account for close to 59% of the install base, the highest concentration of any platform in this category. The Netherlands (5.9%), Spain (2.8%), and France (2.7%) lead the non-English side, and Australia (6.2%) and Canada (5.4%) round out the core.

Sales Signal: Non-profits are underserved and over-engaged, making up 2.72% of installs but a reported 28% of Capterra reviewers. A vertical play targeting them with messaging around donor communication workflows, fundraising campaign automation, and non-profit pricing would resonate. For geographic targeting, the Netherlands and Australia both punch well above their population size, suggesting mature digital marketing cultures where alternatives could gain traction with localized messaging.

Migration Patterns

Migration here counts domains we watched switch since March 2026, so the numbers are small by design and current by construction. The Klaviyo corridor is Mailchimp's clearest vulnerability: 3,113 domains switched from Mailchimp to Klaviyo while only 549 went the other direction, close to a 6:1 ratio, and 2,113 of those departures happened in the last 30 days. The pattern is familiar: ecommerce businesses outgrow Mailchimp's automation and move to Klaviyo for deeper Shopify and WooCommerce integration.

The transactional API corridors run the same direction but at lower volume: 814 left for Mailgun against 180 returning, and 530 left for SendGrid against 90 returning. Those are often additions rather than replacements, a developer wiring up transactional mail while marketing keeps Mailchimp. Brevo is the most balanced corridor at 390 out against 278 in.

Sales Signal: If you sell ecommerce marketing tools, target the 26.58% of Mailchimp domains running Shopify and the 15.81% on WooCommerce. These are the companies most likely to migrate. Use specific messaging: "Your store is generating data that Mailchimp can't act on." For non-ecommerce plays, target the domains running Mailchimp with no marketing automation tool at all, which is the overwhelming majority.

"Two thousand one hundred domains left Mailchimp for Klaviyo in thirty days. That isn't a competitive data point, it's a map of where ecommerce email budgets are moving, and it is moving faster this quarter than last." - Mehmet Suleyman, CEO at TechnologyChecker.io

Tech Stack Ecosystem

WordPress dominates at 41.13% overlap. In ecommerce, Shopify at 26.58% now sits ahead of WooCommerce at 15.81%, so roughly four in ten Mailchimp domains run a storefront of some kind. Squarespace (3.23%) and Drupal (1.1%) round out the CMS picture.

Google Analytics appears on 69.22% of Mailchimp domains, the highest overlap of anything we measure against it. On the payments side Apple Pay (19.75%), Shop Pay (19.66%), and PayPal (19.61%) cluster tightly, which is the Shopify checkout stack showing through.

Sales Signal: The WordPress-plus-Mailchimp stack is still the single most common combination in our database. If your product integrates with WordPress, you have a direct substitution path into 41% of the install base. The Shopify segment is the higher-value target, since that's where the Klaviyo drain is coming from.

G2 Review Signals for Buyers

The G2 data adds a buyer-perspective layer to our technographic analysis. With 980 review mentions on G2, the signal is clear. Mailchimp scores highest for ease of use (223 mentions). Where it falls short: pricing steep (69 mentions). If you're in a sales conversation about Mailchimp, the review sentiment gives you concrete talking points.

Key Takeaways

1. Mailchimp is still dominant. 21.24% market share, #1 in Email Marketing, and 526,676 active domains, flat month over month.
2. The Klaviyo drain is real and accelerating. 3,113 domains gone since March 2026, 2,113 of them in the last 30 days. Ecommerce businesses are the primary defectors.
3. Small business core, enterprise edge cases. 86.3% have 50 or fewer employees. The enterprise names in the data are departmental deployments, not company-wide email infrastructure.
4. Non-profits punch above their weight. 2.72% of installs but a reported 28% of Capterra reviewers. Loyal, engaged, and worth targeting specifically.
5. WordPress is the gateway, Shopify is the battleground. 41.13% overlap with WordPress, 26.58% with Shopify, and that Shopify slice is where the churn is.

Sales Applications

Outreach template for ecommerce Mailchimp users:

"Hi [Name], I noticed [Company] runs Mailchimp alongside [Shopify/WooCommerce]. Our data shows more than 3,000 stores switched from Mailchimp to a store-native email platform in the last five months. Are you seeing gaps in abandoned cart recovery or product recommendation automation? Happy to share what we're seeing from similar [industry] companies."

Targeting strategy: Filter the Mailchimp install base by company size (11-200 employees), ecommerce platform (Shopify or WooCommerce), and geography (US, UK, or Australia). This narrows to the highest-conversion segment: businesses large enough to have budget, running ecommerce, and in markets where alternative awareness is highest.

Competitive angle: Don't lead with "Mailchimp is bad." Lead with the Intuit pricing changes. Many users feel locked into higher tiers after the 2021 acquisition restructured plans. Frame your pitch around value and feature depth, not around bashing the incumbent.

Explore the full Mailchimp install base with company-level filtering at TechnologyChecker.io. Our dataset covers 526,676 active Mailchimp domains with 328,239 enriched companies including industry, size, location, and tech stack data. Use the "Create Lead List" feature to build targeted prospect lists from this data.