For all the innovations in social media, AI-driven ads, and influencer partnerships, email continues to stand out as the most reliable growth engine in modern marketing. 79% of millennials and 57% of Gen Z members liked being contacted by brands via emailIt is one of the few channels that brands truly own, free from algorithms that can suddenly bury content or change distribution overnight. Yet email has also changed dramatically. The era of one-size-fits-all newsletters is over; today, effective email marketing means personalized journeys, cross-channel orchestration, and the ability to act on real-time customer behavior. At the heart of this evolution is automation.
The right email automation platform can transform how a company nurtures leads, helps create high-converting email funnels, activates new users, retains existing customers, and drives recurring revenue. But not all tools are created equal, and the best choice depends heavily on your growth model—whether you’re an ecommerce brand, a SaaS company, or a B2B organization with a long sales cycle. In this article, we’ll explore what makes an automation tool effective, examine the top platforms available in 2025, and unpack how growth marketers are using them to turn ordinary campaigns into scalable revenue machines.
What Growth Marketers Need from Email Automation
Before diving into the tools, it’s important to understand what “good” looks like for modern growth marketing. At its core, email automation needs to handle data with precision, orchestrate customer journeys with flexibility, and provide analytics that reveal not just opens and clicks, but actual business outcomes.
Growth marketers increasingly depend on platforms that can integrate directly with their product or storefront, pulling in customer behavior in real time. A simple list of subscribers is no longer enough; the modern marketer needs to segment users based on actions, preferences, and predictive behaviors. The ability to trigger an automated sequence when someone abandons a shopping cart, completes an onboarding milestone, or crosses a subscription renewal date is the difference between generic outreach and meaningful, revenue-driving communication.
Beyond data and segmentation, orchestration is critical. Marketers need tools that allow them to build entire journeys, with branches and conditional logic that adapt to each customer. A user who ignores three promotional emails should be sent into a re-engagement track, while a loyal buyer who just placed their fifth order might be offered early access to a VIP program. Ideally, these journeys don’t stop at email. SMS, push notifications, and even in-app messages increasingly sit inside the same automation canvas, creating a true multichannel experience.
Finally, personalization and analytics round out the picture. Personalization today goes far beyond inserting a first name. It can include product recommendations drawn from purchase history, dynamically populated images, and even predictive send times based on past engagement. Analytics, meanwhile, must help marketers understand not only whether an email was opened, but whether it led to revenue, retention, or referrals. Without that visibility, optimization is impossible.
Klaviyo: The Ecommerce Powerhouse
Few tools embody this vision more clearly than Klaviyo. Originally designed with ecommerce in mind, Klaviyo has become the default choice for many Shopify and WooCommerce merchants looking to grow through automation. Its strength lies in its flows: automated sequences that can be triggered by everything from abandoned carts to purchase anniversaries. These flows are highly visual, easy to customize, and capable of incorporating SMS and push notifications alongside email.
What makes Klaviyo so effective for ecommerce is its deep integration with storefront data. When a customer views a product, adds it to their cart, or makes a purchase, that information streams directly into Klaviyo in real time. This enables brands to create hyper-relevant messages: a reminder about an abandoned cart that includes the exact product left behind, or a replenishment reminder timed to arrive when a customer is likely running low. Predictive analytics take this a step further, allowing marketers to segment customers based on their likelihood to purchase again or the expected value of their next order.
For growing online stores, Klaviyo provides a comprehensive environment where email isn’t just a communication channel, but a revenue engine. The main drawback is that its pricing scales quickly with both subscribers and SMS usage, making it better suited to brands that are already monetizing effectively and can justify the cost. But for ecommerce growth marketing, few tools offer the same depth of insight and automation.
ActiveCampaign: Flexible Automations with CRM Power
While Klaviyo dominates in ecommerce, ActiveCampaign has carved out a space among businesses that need a more versatile automation system, particularly those balancing both marketing and sales. The platform is best known for its powerful visual automation builder, which allows marketers to design complex journeys with branching paths, conditional logic, and goal tracking. These automations aren’t limited to email—they can also trigger CRM updates, task assignments, and even webhook calls to other systems.
This combination of marketing automation and CRM alignment makes ActiveCampaign a favorite for B2B and service-based businesses. A lead who downloads a whitepaper might enter an email nurture sequence, but that same action can also trigger a sales notification, add points to a lead scoring model, and schedule a follow-up task for a sales rep. Growth marketers appreciate this kind of coordination because it allows them to manage the entire funnel, from awareness to conversion, inside a single platform.
Over the past year, ActiveCampaign has also introduced a more streamlined interface and AI-driven assistance, making its once-daunting automation builder easier to navigate. That said, the platform still requires a disciplined approach to governance. Without clear naming conventions and documentation, automations can quickly become overwhelming. For companies willing to invest the time in structure, however, ActiveCampaign delivers some of the most flexible lifecycle management available today.
Customer.io: Event-Driven Messaging for Product-Led Growth
Not all growth marketing revolves around ecommerce or lead nurturing. For SaaS companies, marketplaces, and product-led businesses, customer journeys are often defined by in-app behavior rather than purchases or form fills. This is where Customer.io excels. Designed to ingest real-time events from apps and backends, it allows companies to trigger messages based on product usage: completing an onboarding step, hitting a usage threshold, or ignoring a key feature.
Unlike tools that rely on static lists, Customer.io thrives on dynamic segmentation. Marketers can define audiences based on virtually any event or attribute, and then build multichannel journeys that include email, SMS, push notifications, and even in-app messages. The addition of webhooks makes it possible to extend automations beyond messaging, orchestrating actions across the entire product ecosystem.
For growth marketers in SaaS, this event-driven approach unlocks a level of personalization that is difficult to achieve elsewhere. A new user struggling to complete onboarding can receive targeted help, while a power user approaching a trial expiration can be nudged toward upgrade options. The trade-off is that Customer.io requires careful planning of event tracking and schema design. Without clean data, its power is limited. But when implemented well, it becomes a growth marketer’s best friend for driving activation, retention, and expansion.
HubSpot: The CRM-Centric Approach
HubSpot remains one of the most recognizable names in marketing automation, and for good reason. Unlike platforms that focus primarily on campaigns, HubSpot places the customer record at the center of everything. Because its CRM is tightly integrated with its marketing tools, HubSpot allows growth marketers to personalize campaigns with first-party customer data and automate handoffs to sales with remarkable ease.
Workflows in HubSpot can automate far more than just emails. They can update properties, create tasks, score leads, and even manage pipeline stages. For B2B organizations where marketing and sales must operate in lockstep, this makes HubSpot particularly valuable. A prospect who engages with a webinar might automatically be routed to a nurture sequence while also triggering a notification for the appropriate sales rep. The result is a more seamless experience for the customer and a more efficient funnel for the business.
However, HubSpot’s sophistication comes at a price. While its free plan includes basic email tools, true automation is only available at paid tiers, and costs rise quickly as companies scale. For organizations that can afford the investment, the benefit is a holistic system where every touchpoint—from ads to email to sales outreach—is connected through a single CRM-powered platform.
Brevo: Multichannel Automation on a Budget
Formerly known as Sendinblue, Brevo has positioned itself as the accessible option for teams that want solid automation without enterprise-level complexity or cost. It combines email, SMS, and even WhatsApp messaging in a clean, approachable interface. While it doesn’t offer the same depth of segmentation or predictive analytics as tools like Klaviyo or Customer.io, it covers the essentials well and is priced transparently, making it popular among small to midsize businesses.
Brevo’s strength lies in its simplicity. Setting up a welcome sequence, abandoned cart reminder, or promotional campaign is straightforward, and the platform includes built-in features like forms, transactional email, and even a lightweight CRM. For businesses that need to get automation up and running quickly without a steep learning curve, Brevo is an appealing choice. Its reporting is basic compared to enterprise tools, but for many lean teams, the balance between functionality and cost is exactly what they need.
Omnisend and Drip: Streamlined Ecommerce Options
Two other players worth highlighting are Omnisend and Drip, both of which cater primarily to ecommerce brands. Omnisend is known for its prebuilt automations and ability to combine email, SMS, and push notifications in the same workflow. Its templates are especially useful for small teams that need to deploy best-practice flows—like welcome sequences, cart abandonment, and post-purchase follow-ups—without building them from scratch.
Drip takes a similar approach but emphasizes a clean, user-friendly interface and deep store integrations. Its library of ecommerce-specific workflows makes it easy to launch revenue-driving campaigns quickly, and its analytics tie performance directly to sales. Neither Omnisend nor Drip is as feature-dense as Klaviyo, but both excel at delivering a more focused, less overwhelming experience for growing online stores.
Building Growth Through Automation
Choosing a platform is only the first step. The real magic happens in how growth marketers design and refine their automations. A welcome series that introduces a brand and sets expectations can dramatically increase engagement. Behavioral flows, such as cart abandonment reminders or onboarding nudges, consistently rank among the highest ROI automations. Post-purchase campaigns not only drive repeat sales but also strengthen customer loyalty. And win-back sequences can rescue lapsed customers before they churn for good.
The best growth teams treat automation as an ongoing experiment. They test subject lines, incentives, and timing, analyze performance, and refine accordingly. They also pay attention to negative signals—recognizing when a subscriber is disengaged and shifting them into value-driven content rather than endless promotions. Increasingly, advanced teams extend automations beyond messaging, using webhooks to trigger loyalty rewards, API calls, or even Slack alerts that tie marketing into broader business processes.
Conclusion: Matching the Tool to the Motion
Email automation is no longer about blasting newsletters on a fixed schedule. It is about orchestrating personalized, multichannel journeys that respond to customer behavior in real time. For ecommerce brands, platforms like Klaviyo, Omnisend, and Drip provide deep integrations and proven revenue flows. For SaaS and product-led companies, Customer.io offers unparalleled event-driven messaging. For businesses that need the flexibility of both marketing and CRM, ActiveCampaign and HubSpot deliver lifecycle automation that spans from first touch to closed deal. And for smaller teams on a budget, Brevo remains a practical, approachable option.
Ultimately, the best email automation tool is the one that mirrors your growth model. Choosing wisely means understanding not only what each platform can do, but also what your business truly needs. With the right foundation, email automation doesn’t just scale communication—it compounds growth.
