Every eCommerce business wants to increase revenue—but acquiring new customers is often far more expensive than nurturing existing ones. This is where cross-selling and upselling come in. When done strategically, these techniques can increase order value, improve customer satisfaction, and boost lifetime value. And one of the most effective channels for executing them? Email.

Email marketing is uniquely positioned to support personalised product recommendations at just the right time. It allows you to reach customers post-purchase, during browsing, or even at checkout, using automation and behaviour-driven triggers. Done well, cross-sell and upsell emails feel helpful—not pushy—adding genuine value to the customer’s experience.

Understanding the Difference

Though often used interchangeably, cross-selling and upselling are distinct strategies. Cross-selling encourages customers to buy complementary products. For instance, if someone purchases a camera, a cross-sell email might suggest a memory card, tripod, or camera bag.

Upselling, on the other hand, persuades customers to upgrade or purchase a more premium version of a product. A customer looking at a basic laptop might be shown one with more features or a better processor at a slightly higher price.

Both techniques aim to increase the average order value, but they do so in different ways. Used in tandem, they offer a powerful way to grow your revenue without increasing customer acquisition costs.

Why Email Works So Well for This

Unlike on-site prompts, which rely on the customer still being actively engaged in the shopping session, email allows you to follow up and continue the conversation later. It’s non-intrusive and can be timed to hit when the customer is most likely to be receptive—after a purchase, during a browse session, or when they're due to reorder.

More importantly, email gives you the chance to personalise. With access to purchase history, browsing behaviour, and preferences, you can suggest products that are genuinely relevant. This doesn’t just boost conversions—it builds trust.

Timing Is Everything

The effectiveness of cross-sell and upsell emails often comes down to timing. A post-purchase window is one of the best opportunities. If a customer buys a skincare product, for example, an email sent a few days later might recommend a matching cleanser or a value bundle with additional items from the same range.

Another good moment is during a cart or browse abandonment sequence. If someone’s shown interest in a product but hasn’t converted, an upsell email might offer a more popular version with better reviews or a bundled discount that encourages them to spend slightly more.

You can also take a longer-term view. A few weeks after delivery, an email that invites the customer back with relevant product suggestions—based on what they bought—can drive re-engagement and further sales without needing to offer discounts.

Making It Feel Natural, Not Pushy

The key to success with these emails is subtlety. You’re not just trying to sell more—you’re trying to help more. Recommendations should feel timely, relevant, and customer-focused. Highlight the benefits of the additional or upgraded product, and explain why it complements or improves the original purchase.

Avoid bombarding the customer with too many unrelated suggestions. One or two well-chosen products are far more effective than a long list. Use language that’s helpful and informative, rather than overly salesy.

Design also plays a role. Clear product imagery, simple descriptions, and a straightforward call-to-action can significantly improve click-through and conversion rates. If you’re upselling, make sure the added value of the upgrade is obvious—whether it’s better features, longer lifespan, or exclusive benefits.

Automation Makes It Scalable

With the right email platform in place, cross-sell and upsell emails can be fully automated based on specific customer behaviours. You can create workflows that trigger when someone completes a purchase, views a particular product category, or hits a certain milestone.

For example, a customer who buys running shoes might automatically enter a flow that introduces them to socks, performance wear, or a hydration belt over the next few days. These sequences feel personal and timely because they’re based on real actions—not random blasts.

To do this effectively, it helps to work with an experienced Email Marketing Agency that understands how to build behavioural triggers, design intuitive customer journeys, and optimise content for conversions.

Final Thoughts

Cross-selling and upselling through email isn’t just about squeezing more out of your customers—it’s about enriching their experience. When done thoughtfully, these strategies help customers discover products they genuinely need or may not have thought to purchase otherwise.

By combining personalisation, automation, and great timing, you can turn one-time shoppers into repeat buyers—and small purchases into higher-value transactions. As your eCommerce brand grows, these incremental gains play a major role in long-term profitability.

Email gives you the perfect platform to make it happen. Start small, stay strategic, and build trust with every message.