The Science of Selling More: How to Write Upsell Emails That Convert

If you‘re not upselling, you‘re leaving money on the table. Upselling is one of the most effective ways to increase customer lifetime value (CLV) and revenue without having to acquire net new customers. Consider these statistics:

• Upselling increases revenue by 10-30% on average (Sumo)
• The probability of selling to an existing customer is 60-70%, compared to just 5-20% for a new prospect (Invesp)
• It costs 5x more to acquire a new customer than retain an existing one (Invesp)
• Upsells and cross-sells account for 10-30% of ecommerce revenue (Forrester)

But not all upsell attempts are created equal. Consumers are savvy and can smell a lazy upsell pitch from a mile away. To be effective, your upsell emails need to be timely, relevant, and genuinely valuable to each individual recipient.

In this comprehensive guide, we‘ll share proven practices for crafting upsell emails that drive more sales and happier customers. Whether you‘re an ecommerce brand, SaaS business, or B2B vendor, these principles can improve the persuasive power of your campaigns.

Upselling vs. Cross-Selling

Before we dive in, let‘s clarify some terminology. While often used interchangeably, upselling and cross-selling are slightly different:

• Upselling encourages customers to buy a higher-end version of a product they‘re already considering or have purchased. Examples: upgrading to a premium subscription, adding more storage to a phone.

• Cross-selling encourages customers to purchase a related or complementary product in addition to the main item. Examples: adding a protective case to a laptop purchase, buying fries with a burger.

The email tactics covered here apply to both scenarios, but most of the examples will focus on upselling. Just remember that with cross-selling, the add-on should be positioned as a way to enhance the use or enjoyment of the core product.

7 Keys to High-Converting Upsell Emails

1. Personalize based on behavior and preferences

The days of "batch and blast" email are over. Today‘s consumers expect a high degree of personalization in all brand communications. In fact, 91% say they‘re more likely to shop with brands that provide relevant offers and recommendations (Accenture).

Effective personalization requires a robust understanding of each individual customer‘s needs, preferences and behaviors. The more data you can collect and segment, the better you can tailor upsell offers to each person‘s unique context.

Some data points to leverage for personalizing upsell emails:

• Purchase history
• Item categorization and attributes
• Lifecycle stage and customer tenure
• Demographic info like age, gender, location
• Email engagement (opens, clicks, etc.)
• Website activity and browsing behavior
• Loyalty program status

Using this data, you can trigger specific upsell emails based on relevant actions, or dynamically populate content based on a user‘s profile. For example:

• Product Category: Show a higher-end option for the same category 1 week post-purchase
• Price Sensitivity: Offer a discount on an upgrade if a user has only purchased from the sale section
• Use Case: Recommend a faster, more powerful version of a tool for power users
• Timing: Provide an annual plan upgrade offer 2 months before a monthly subscription renews

No matter what system you use to trigger and customize upsell emails, the goal is to show customers that you understand and care about their individual needs. Aberdeen found that personalized email messages improve click-through rates by an average of 14% and conversions by 10%.

2. Highlight benefits, not features

One of the biggest mistakes in upsell emails is focusing on the incremental improvements or additions in the upsell product. Most customers don‘t care about a bigger number on the spec sheet – they care about how those enhancements will benefit them personally.

The key is to translate features into meaningful benefits that align with the customer‘s goals and pain points. How will this upsell make the customer‘s life easier, better, or more enjoyable? What end result will it help them achieve?

Consider this before-and-after example for a project management software:

Feature-Focused: "Upgrade to ProjectPro to get 5 GB of additional storage and priority support."

Benefit-Focused: "Upgrade to ProjectPro and take your productivity to new heights. With 5x the storage, you‘ll have room for all your files and assets in one place. Plus, our priority support is like a concierge for your projects – you‘ll spend less time troubleshooting and more time leading your team to success. Get it now for just $10 more per month."

See how the second version paints a picture of how the customer will be better off with the upsell? It taps into their desire to be organized and efficient, rather than just listing off product attributes.

To uncover the core benefit of an upsell feature, ask yourself:

• What customer need or problem does this feature solve?
• How will the customer‘s work or life be improved by using it?
• What positive outcomes will it help the customer achieve?
• What negative consequences will it help the customer avoid?
• How is it better than the default or a competitor‘s version?

Answering these questions will get you in the mindset of showcasing true value, not just extra bells and whistles.

3. Create authentic urgency

We‘re all prone to procrastination, especially when it comes to spending more money. Creating genuine urgency in your upsell emails is an effective way to inspire action and reduce decision paralysis.

Common urgency tactics include:

• Limited-time discounts or bonuses
• Low inventory or limited availability warnings
• Seasonal or event-related promotions (holidays, end of month/quarter)
• Special pricing for a customer‘s first upsell purchase
• One-click upsells with a short acceptance window

When using urgency, it‘s important to strike a balance between helpful and hammy. If every upsell email screams "LAST CHANCE!" or "ALMOST GONE!", your claims will start to lose credibility. Urgency is most effective when used sparingly and tied to legitimate limitations.

One way to preserve authenticity is to back up urgency with real numbers. For example, instead of just saying "Going fast!", you could show real-time inventory levels or purchases, like this:

Example of using real data to convey urgency (Source: Author)

You can also use dynamic countdown timers to create a sense of urgency in a genuine way. These timers can be set to expire at a fixed time (e.g. end of day) or a relative time based on when the email is opened.

Example of a dynamic countdown timer (Source: Author)

Just remember: Urgency is a spice, not the main course. It should enhance your upsell emails but not overpower the central narrative of why the upgrade is valuable to begin with.

4. Provide social proof

As social creatures, we‘re heavily influenced by the opinions and behaviors of others. Numerous studies have shown that social proof can be a powerful motivator in purchasing decisions.

Types of social proof to leverage in upsell emails include:

• Customer reviews and ratings
• Usage or sales numbers (e.g. "Join 10,000+ happy customers who have already upgraded")
• Celebrity or influencer endorsements
• Media mentions and awards
• Customer testimonials and case studies

For maximum impact, try to use social proof that is specific to the upsell product or tier. A wall of 5-star reviews for your brand is nice, but a glowing quote calling out the specific benefits of upgrading is more likely to resonate.

Ideally, social proof should come from people who resemble your target customer persona. We‘re more apt to trust people who seem similar to us in terms of industry, job title, use case, etc.

Example of social proof in an upsell email (Source: Author)

Social proof is most powerful when used as supporting evidence, not the primary hook. Lead with the benefits of the upsell, then use social proof as an assist to build credibility and address potential objections.

5. Make your CTA impossible to miss

You could write the world‘s most compelling upsell copy, but if the call-to-action is buried or unclear, you won‘t get the click. Your CTA should practically jump off the screen.

Best practices for upsell CTAs in email:

• Placement: Position CTAs in prominent locations, typically after a key benefit statement or block of social proof. Avoid placing them too close to other links that could cause misclicks.

• Color: Use a contrasting color for your CTA button that stands out from the background and surrounding text. Orange, green, and red tend to perform well.

• Copy: Keep CTA copy brief and action-oriented. Focus on the key benefit or end result, like "Double My Storage" or "Upgrade Now & Save 20%".

• Design: Make sure CTAs look clickable, with a 3D effect or arrow icon. The button should be large enough to tap easily on mobile (minimum 44×44 pixels).

• Repetition: Include the CTA at least 2-3 times for longer emails, especially if you need to scroll to see the entire message. Bring it back after each major selling point.

• Singular: In most cases, upsell emails should have a single call-to-action. Including multiple CTAs can lead to decision paralysis and depress conversions.

Example of a clear, benefit-focused CTA (Source: Author)

Remember, the goal is to make taking action as frictionless as possible. Don‘t make the user hunt for the CTA or decipher vague button copy. Be clear, direct, and enthusiastic.

6. Follow accessibility guidelines

With email, you‘re reaching a wide audience of people with varying levels of ability when it comes to vision, hearing, mobility, and cognition. Failing to make your upsell emails accessible means you‘re excluding a significant portion of potential customers.

Accessibility is both a moral imperative and a business one. It‘s estimated that the global population of people with disabilities has a disposable income of $1.2 trillion. Brands that ignore accessibility are leaving serious money on the table.

Some key accessibility considerations for upsell emails:

• Visual Contrast: Maintain a high contrast ratio between text and background colors, at least 4.5:1 for small text and 3:1 for large text.

• Semantic Structure: Organize content with descriptive headings (H1, H2, etc.), and use HTML list elements to group related items.

• Image Alternatives: Provide descriptive alt text for images. Limit text overlayed on photos, which can be hard to read.

• Readable Fonts: Use simple, sans-serif fonts, ideally 14 pixels or larger. Avoid playful but impractical novelty fonts.

• Keyboard Friendliness: Make sure users can tab through and interact with links and buttons using a keyboard, not just a mouse.

• Accessible Code: Use semantic HTML elements. Specify the code language. Provide ARIA roles and labels for dynamic or interactive content.

Following these guidelines won‘t just improve usability for people with disabilities – they‘ll make your emails more effective for everyone. Clarity, simplicity, and scannability benefit all readers.

7. Test and optimize continuously

No matter how much research and best practice expertise you bake into your upsell emails, you‘ll never know exactly what works for your specific audience until you test.

Common email elements to test for upsell campaigns:

• Subject lines
• Headings and body copy
• CTAs (copy, color, placement)
• Offers (e.g. discounts vs. bonuses)
• Social proof
• Product recommendations and bundles
• Send timing and frequency

The key to effective testing is a scientific approach. Start with a hypothesis for what you think will work, then test that variant against a control version of your email. Make sure to test with an adequate sample size and let the test run long enough to reach statistical significance.

Some tips to keep your testing program disciplined:

1. Test one variable at a time to pinpoint causality
2. QA thoroughly to avoid errors skewing results
3. Consider running tests simultaneously to mitigate timing effects
4. Measure micro and macro metrics, like clicks and revenue per email
5. Document results and share learnings across teams
6. Feed insights into future test hypotheses for continuous improvement

Remember, there are no universal right answers in email optimization. What works for one audience may fall flat for another. Stay curious, question assumptions, and let the data guide your upsell strategy.

Putting It All Together

We‘ve covered a lot of ground in this guide, so here‘s a handy checklist to make sure you‘re hitting all the marks with your upsell emails:

The Anatomy of an Irresistible Upsell Email

• [ ] Personalized based on user data and behavior
• [ ] Focused on customer benefits, not just features
• [ ] Creates authentic urgency with real offers and deadlines
• [ ] Leverages relevant social proof like reviews and testimonials
• [ ] Has a clear, contrasty call-to-action that‘s impossible to miss
• [ ] Follows accessibility best practices for inclusive design
• [ ] Uses insights from past tests to optimize performance

Of course, following these guidelines is just the beginning. Your work isn‘t done until you have a well-oiled upsell machine that consistently delivers better experiences for customers and better results for the business.

But by putting these foundational principles into practice, you‘ll be well on your way to creating high-converting upsell emails. Your customers will appreciate the thoughtful, value-added touch, and your bottom line will reflect the power of a strategic upsell program.

Now get out there and start sending more revenue-generating emails. Your future self (and your sales team) will thank you.