The ultimate guide to retention emails: How to drive loyalty and revenue

With the rising costs of acquiring new customers, some marketers argue that retention should be the new acquisition. And they’re not wrong — especially if your goal is to maximize customer lifetime value.

Brands that prioritize retention don’t have to constantly chase new customers just to maintain revenue, avoiding the need to burn through their marketing budgets. They understand that real growth comes from keeping the customers they already have. And when it comes to retention, no channel is more effective than email marketing.

Think about it — your customers have already given you permission to reach them via email. That makes it the most direct, cost-effective, and personalized way to engage them (unless you plan to knock on their doors to promote your latest product, but let’s be honest — that probably wouldn’t go so well).

So, join us as we break down everything you need to know about retention email marketing — from real-world examples to actionable insights.

Why choose email marketing for customer retention?

As we’ve already touched on, the direct nature of email makes it the perfect tool for building long-lasting customer relationships. Unlike paid ads, where you’re constantly spending to reach your audience, or social media, where third-party algorithms can change overnight, email gives you full control over your communication.

One of its biggest advantages is that your audience is “owned” rather than “rented.” Your email list is an asset — you’re not at the mercy of fluctuating ad costs or unpredictable platform changes.

Email also consistently outperforms other channels in engagement and, most importantly, return on investment (ROI). According to Omnisend’s internal analysis, merchants achieve an average ROI of $68 for every $1 spent — a figure rarely seen in other marketing channels.

Beyond cost-effectiveness, today’s email marketing platforms offer powerful tools for creating highly personalized and engaging experiences. With advanced segmentation and automation, you can deliver hyper-relevant messages based on customer behavior and the lifecycle stage. And it’s not just for promotions — email plays a crucial role at every step of the customer journey:

• acquisition: Welcome and onboard your customers, introduce your brand, and offer an exclusive discount to set the right tone;
• engagement: Send out post-purchase follow-ups, personalized product recommendations, or educational content to further build loyalty;
• re-engagement: Identify inactive customers and bring them back with win-back campaigns designed to reduce churn.

Retention goals and KPIs

What does retention mean for your brand?

Retention is a broad term that can mean different things depending on your business model, so the goal is to define what success looks like for you. For example:

• eCommerce businesses focus on increasing repeat purchases and reducing churn;
• subscription-based businesses prioritize driving renewals and minimizing cancellations;
• B2B and SaaS companies measure success through product adoption and long-term engagement;
• content-driven brands aim to maintain consistently high engagement rates.

This is the foundation of your retention strategy, so take the time to set clear, measurable goals. If it’s increasing repeat purchases, what percentage are you aiming for? If it’s increased customer lifecycle value, what specific figures are you targeting? Defining these benchmarks up front can then guide your strategy and approach.

Key email retention metrics to track

If you’re just starting out, here are some key email retention metrics you can track to measure the effectiveness of your strategy:

• repeat purchase rate: This measures the percentage of customers who return to buy again. A high repeat purchase rate signals strong retention. And if it’s lower than you’d like it to be, you should consider updating your post-purchase communication (incentives, loyalty programs);
• churn rate: Churn refers to the percentage of customers who stop engaging with your brand, whether that means they’ve unsubscribed from emails, stopped opening them, or haven’t made another purchase. The goal is always to minimize the churn;
• customer lifetime value (CLV): CLV represents the total revenue a customer generates throughout their relationship with your brand. The higher your retention, the higher your CLV;
• engagement rate: These are your classic email performance metrics, such as open rates, click-through rates (CTR), and time spent engaging with emails. High engagement rates indicate that your content is resonating with your audience;
• unsubscribe and spam complaint rates: These are red flags that signal subscribers are disengaging or finding your emails irrelevant. A high unsubscribe rate suggests that your emails may be too frequent, too sales heavy, or not aligned with customer expectations. Spam complaints are even more damaging, as they can hurt your sender reputation and deliverability.

How to set up retention benchmarks for your industry

There’s no surprise that different industries will see different results. So, you need to set benchmarks that are realistic to your case rather than chasing arbitrary numbers. 

You can start by:

• looking at historical data to determine your baseline retention metrics;
• comparing industry averages, as retention rates vary widely by sector;
• analyzing competitors where possible to see what’s realistic for your niche;
• tracking improvements over time and A/B testing different strategies to refine your approach.

This will give you a solid foundation that is based on your specific case because success means different things to different people and businesses.

6 main types of retention emails

Let’s take a look at different types of retention emails and how brands are implementing them in real life. 

1. Welcome and onboarding emails

Retention strategy starts at the very beginning of your new customer’s journey. That’s why it’s important to set the right tone with welcome and onboarding email sequences. There could be many different approaches to this, but you should always try to show the value of your product and guide the customer through the necessary steps to get the most out of what you’re selling. 

Take Navan’s onboarding email, for example:

(Source: Email Love)

This is a strong example of an effective onboarding message. Here’s why it works well:

• warm, inviting imagery immediately sets a positive and engaging tone;
• step-by-step structure guides subscribers through key actions to set up their accounts;
• concise, benefit-driven copy keeps instructions digestible and focused on ease.

2. Post-purchase emails

A customer making a purchase is just the beginning — post-purchase emails help maintain engagement, build loyalty, and encourage repeat sales. These emails should reinforce the value of the purchase, educate customers on how to get the most out of their product, and keep them connected to your brand.

Here’s how Hims is doing this:

(Source: Email Love)

The brand is continuing to engage its customers by educating them and positioning itself as an expert in the industry. Here’s why it works:

• bold, reassuring headline reinforces success and builds confidence in the recipient’s decision;
• clear, action-driven CTA (“Set up now”) encourages immediate engagement with the product;
• helpful “hot tip” section provides practical advice to improve consistency and product effectiveness;
• support link (“Visit the Help Spot”) ensures subscribers have easy access to assistance, reducing friction.

3. VIP and loyalty program emails

We all want to turn our customers into superfans. Well, by offering exclusive perks, early access, or personalized rewards, you’d definitely be one step closer. In this case, brands can really benefit from smart segmentation to determine their most loyal customers and send content curated specifically for them.

Take a look at this example from SRF Club:

(Source: Email from SRF Club)

This email is a great example of how a well-crafted loyalty message can drive engagement by making rewards feel tangible and exciting. Here’s why it works well:

• celebratory tone (“celebrate with more rewards”) makes customers feel valued and excited;
• personalized details (“You have 309 points”) reinforce engagement and encourage redemption;
• strong incentive with new perks (“8 NEW reward items”) creates urgency and exclusivity.

4. Replenishment and reorder emails

For consumable products, replenishment emails serve a double purpose — you’re showing that you care about your customers not running out of the product while at the same time driving repeat purchases. Automating these reminders based on purchase cycles and customer behavior keeps the buying process effortless.

Graza is a great example:

(Source: Email Love)

This email cleverly encourages customers to restock their olive oil while reinforcing brand engagement through helpful content. Here’s why it works well:

• step-by-step guide makes replenishing easy and removes any friction from the process;
• playful, branded language (“Squeeze your heart out”) keeps the email fun and on-brand;
• recipe suggestions add value beyond the product, keeping subscribers engaged;
• vibrant, lifestyle-driven visuals create a warm, aspirational feel that resonates with food lovers.

5. Win-back and re-engagement emails

Not all inactive customers are lost — sometimes they just need a nudge to return. Win-back emails help identify at-risk customers, giving you one more chance to reignite engagement before they fully churn. Look for signs like declining email opens and use personalized incentives, feature updates, or friendly reminders of why they loved your brand in the first place.

This is how Levi’s does it:

(Source: Email Love)

This email effectively re-engages inactive subscribers with a conversational, lighthearted approach that makes opting back in feel effortless. Here’s why it works well:

• chat-style format creates a personal and relatable feel, mimicking real-life conversations;
• casual, friendly tone lowers the pressure and makes re-engagement feel natural;
• clear opt-in choice (“KEEP ME SUBSCRIBED” vs. “UNSUBSCRIBE”) gives recipients control;
• soft exit messaging (“We’ll miss you, but we understand”) prevents negative feelings and leaves the door open for future engagement.

6. Milestone and anniversary emails

Celebrating milestones — customers’ or brands’ birthdays, purchase anniversaries, or VIP achievements — creates personalized moments that strengthen brand affinity. By offering a gift, discount, or exclusive perk, you can make customers feel valued and encourage repeat engagement.

Take Health-Ade’s birthday email, for example:

(Source: Email Love)

This email does a great job of celebrating a brand milestone while incentivizing customers to engage with a limited-time offer. Here’s why it works well:

• bold, celebratory headline (“3 Years of Glowing”) immediately sets the tone;
• clear discount offer (20% off with code GLOWUP20) creates urgency and drives conversions;
• product highlights reinforce value by showcasing the unique benefits of each flavor;
• creative CTA (“Start Glowing”) encourages immediate action.

Retention email marketing: Best practices

It should be clear by now that retention emails are anything but generic messages. They are targeted, automated, and designed to engage. When in doubt, refer to these best practices to keep your retention strategy on point: 

1. Segmentation and personalization: Not all subscribers are the same, and your emails shouldn’t be, either. Use customer data to create segments based on behavior, purchase history, or engagement levels. Personalization, from using the recipient’s name to recommending products based on past purchases, makes emails even more relevant and effective.
2. Automation vs. manual campaigns: Automated emails (such as welcome sequences, replenishment reminders, and win-back campaigns) ensure timely engagement without extra effort. However, manual campaigns, such as seasonal promotions or exclusive offers, allow flexibility and human touch. A strong retention strategy blends both.
3. Copywriting and design: Retention emails should be clear, engaging, and easy to skim. Use concise, benefit-driven copy that focuses on value rather than just promotions. Design-wise, a clean layout, strong visuals, and a compelling CTA help guide the reader toward action.

Wrapping up

One thing is clear — retention marketing is about relationships. And the brands that master this aren’t the ones with the biggest lists but the ones that know how to keep their subscribers engaged, valued, and coming back for more.

Every type of retention email plays a role in customer journeys and is an effective way to drive revenue, increase customer lifetime value, and make your marketing budget work harder. So, take what you’ve learned here and start refining your retention strategy, because your next best customer is the one you already have.