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Enhancing Your Email Campaigns: Best Practices for Incorporating Customer Testimonials

Published on
June 1, 2024

Table of contents

Email marketing remains a cornerstone of effective digital communication, offering a direct line to your audience's inbox. But in an era where consumers are bombarded with countless emails daily, standing out is more crucial than ever. 

Incorporating customer testimonials into your email campaigns can significantly enhance credibility and foster engagement. Testimonials serve as social proof, reassuring potential customers about the quality and reliability of your product or service. 

Emails with customer testimonials see an average conversion rate increase of 15% compared to emails without testimonials. Moreover, 92% of consumers trust recommendations from friends and family, while 70% trust recommendations from other consumers posted online, including testimonials in emails, can tap into this trust.

In this post, we'll explore the best practices for weaving customer testimonials into your email marketing strategy to captivate your audience and drive conversions.

Selecting the Right Testimonials

Relevance is Key

It's not merely about showcasing positive feedback; it's about ensuring the testimonials resonate deeply with the intended recipients. Relevance is the cornerstone here. 

The testimonials chosen must align closely with the demographics, preferences, and pain points of the target audience. Receiving testimonials that mirror their experiences or aspirations fosters a sense of connection and trust. 

Hence, meticulous attention to relevance is crucial for the effectiveness of your email campaigns. The next cornerstone is diversification. 

Diverse Voices

Variety breeds resonance and inclusion. Every customer segment within your audience is unique, with distinct needs, perspectives, and challenges. By incorporating testimonials from a diverse range of voices, you demonstrate inclusivity and cater to the multifaceted nature of your audience. 

Whether it's showcasing testimonials from different industries, demographics, or product use cases, embracing diversity enriches the credibility of your message. It ensures that no segment feels overlooked and enhances the relatability of your email campaigns, thus maximizing their impact.

Source: Inclusion of Diverse Voices in Code Academy’s Testimonials

Authenticity Matters

In an age where consumers are increasingly discerning, genuine testimonials carry immense weight. Authentic testimonials aren't just about singing praises; they encapsulate real-life experiences, both positive and negative, in the customer's own words. 

Authenticity instills confidence by demonstrating transparency and integrity. It's about letting the raw, unfiltered voice of your customers speak volumes about your brand's credibility.

Genuine testimonials resonate deeply because they aren't scripted marketing jargon but real narratives of satisfaction and fulfillment.

Source: Simple Green’s testimonials look authentic and real

Crafting Compelling Testimonial Content

Structuring your email

Catchy Subject Line and Preheader

The storytelling experience of your mail starts with the Subject Line. Subject lines like "Discover How [Customer] Achieved [Specific Result] with Our Product!" or preheaders like "Read Our Latest Success Story and See How Our Product Transformed [Customer]'s Business!" can intrigue and engage your recipient immediately and compel them to open the email. Your subject line is to email like thumbnails are to YouTube videos. 

Including customer testimonials in the email subject lines can increase email open rates by 7%, and including them in the email body can increase click-through rates by 34%.

Body Content

  • Introduction: Start with a brief introduction highlighting the success story you're about to share.
  • Testimonial/Customer Quote: Incorporate a compelling quote from the customer about their experience with your product or service.
  • Case Study Overview: Provide a brief overview of the customer's challenges, goals, and the solution provided by your product/service.
  • Results and Benefits: Detail the specific results achieved by the customer, including quantifiable metrics or improvements.
  • Call to Action: Encourage readers to take action, such as visiting your website to read the full case study or trying out your product/service.

Brevity and Clarity

To maintain the reader's attention and convey the essence of the testimonial effectively, it's crucial to keep it concise and clear. Encourage customers to focus on the most impactful aspects of their experience, avoiding unnecessary details or jargon. 

Bullet points or short paragraphs can help present information in a digestible format. By trimming the fat and getting straight to the point, you ensure your testimonials pack a punch without losing the reader's interest.

For example, consider the following email by Cladwell.

Source: Cladwell has compressed the stories of their customers into short digestible bites
Source: Cladwells’ “Read More Stories” button for engaging the customer deeper into testimonials

Storytelling Approach

Humans are wired to connect with stories. By framing testimonials as narratives that unfold a customer's journey, you transform mere endorsements into compelling tales that resonate on an emotional level.

Encourage customers to share not just what they liked about your product or service but also the challenges they faced, the solutions they found, and the transformation they experienced.

By weaving a narrative arc with a beginning, middle, and end, you engage readers on a deeper level and make the customer journey relatable. Stories can evoke empathy, spark curiosity, and inspire action, making them a potent tool for capturing attention and driving engagement in testimonials.

Source: Danner’s customer testimonial telling the story of the shoe being versatile and accessible in a single-line

Consider the email below. This email is quite engaging and evokes an emotion of laughter and humor. Notice how it has formatted the text so the funnier parts in the text are larger than the rest. That just makes it more readable and catchy to the eye. This formatting and the funny narrative in the reviews are also a part of the storytelling. 

Source: Magic Spoon’s testimonial consisting of humorous reviews

Visual Elements 

A picture is worth a thousand words, and this holds true for testimonials as well. Including visual elements such as customer photos or videos and reviews can significantly enhance authenticity and connection. 

Seeing real faces and genuine expressions adds credibility to the testimonial, reinforcing that these people are sharing their experiences. Moreover, visuals can evoke emotions and create a lasting impression in ways that text alone cannot.

Also, it’s not just about including the right pictures or videos in your emails; it’s the entire design as a whole that speaks of your brand and your messaging and plants a deeper seed in the mind of the receiver. 

For example, the image below is quite well-designed, has a human element in the picture, and has an “As Seen In” section that highlights media coverage that socially proves the products and adds more legitimacy and credibility to the brand. 

It has another line, “10,000 people worldwide love…” that further acts as social proof. In terms of design, the product is well highlighted. Everything follows a color scheme: borders, company logos, aesthetic fonts, symmetry, and more design-enhancing elements. 

Source: BUOY’s well-designed email testimonials and reviews

Include Statistics

Utilizing numbers within your subject lines or body can effectively spotlight quantifiable benefits or features of your product or service. This approach grabs the reader's attention and provides a clear and concise preview of your email's value proposition.

For instance, consider crafting subject lines such as "Unlocking Efficiency: 5 Ways Our Product Has Transformed [Customer]'s Business" or "Witness Success: 7 Impressive Results Achieved with Our Product". You instantly convey tangible advantages by quantifying the benefits or outcomes, compelling recipients to open your email and explore further.

Source: email consisting of numbers and quantifiable benefits in a testimonial 

Finally, the image below is a great example of all the above-mentioned tips. The email consists of: 

  • a single-line testimonial that tells a great story
  • A good design with the company logo
  • Real, attractive, and well-clicked images of cats 
Source: SMALL’s email testimonials - a perfect example of storytelling, good design, and a good story

Strategic Placement in Emails

Subject Lines and Preheaders

The battle for attention in crowded inboxes begins with the subject line. By incorporating compelling testimonial snippets into your subject lines or preheaders, you pique the recipient's curiosity and increase the likelihood of your email being opened. 

Testimonials act as social proof, instantly grabbing attention and signaling the value proposition of your email. Consider using concise and impactful quotes from satisfied customers highlighting key benefits or outcomes.

Body Content Integration

Integrating testimonials seamlessly within the body of your email is crucial for ensuring they enhance rather than disrupt the overall message and call to action. One effective strategy is strategically placing testimonials at relevant points within the email content. 

For example, if introducing a new product or feature, include a testimonial from a satisfied customer who experienced its benefits firsthand. Additionally, you can use testimonials to reinforce key points or benefits mentioned in the email, providing social proof to support your claims.

Source: Eight Sleep’s well-integrated and placed testimonials within the email


Creating segmented email campaigns allows you to deliver tailored content, including testimonials, to specific groups within your audience. By segmenting your audience based on factors such as demographics, purchase history, or browsing behavior, you can better understand their needs and preferences and deliver highly relevant content.

Regarding testimonials, segmented campaigns enable you to showcase customer experiences that align closely with the interests and priorities of each group. For example, if you offer a range of products or services catering to different industries, you can tailor testimonials to highlight success stories relevant to each industry segment. 

Similarly, if you use Google ads or Pixel, you can use that data to segment your emails. You can segment them based on their purchase behavior, whether they are a frequent customer, a one-time shopper, etc. 

In the same way, you can segment your audience based on their stage in the customer journey and provide testimonials that address their specific concerns or objections at each stage.

Source: Email Segmentation Categories

By delivering targeted testimonials to segmented groups, you increase the likelihood of capturing their attention and driving meaningful engagement.

Measuring Success and Optimizing Strategy

Tracking Engagement

To gauge the impact of testimonials on email engagement rates, it's crucial to implement methods for tracking various metrics such as click-through rates (CTR) and conversion rates. Most email marketing platforms offer robust analytics tools that allow you to monitor the performance of your campaigns in real time.

Start by segmenting your email list to compare the engagement rates of recipients who received emails with testimonials against those who didn't. Analyze metrics like CTR to determine if emails featuring testimonials drive higher engagement levels. 

Additionally, track conversion rates to assess whether testimonials influence recipients to take desired actions, such as purchasing or signing up for a service.

Source: engagement metrics on email

By closely monitoring these metrics over time, you can gain insights into how testimonials impact your email campaigns' overall effectiveness and make data-driven decisions to optimize your strategy.

A/B Testing

A/B testing is a powerful technique for optimizing your testimonial strategy by comparing different variables such as testimonials, placements, and formats to identify what resonates best with your audience.

Start by creating multiple versions of your emails, each featuring different testimonials, placements (e.g., in the subject line, body, or dedicated section), or formats (e.g., text-based testimonials vs. video testimonials). Then, randomly assign segments of your email list to receive each version and track the performance of each variant using metrics like open rates, CTR, and conversion rates.

Continuous Feedback Loop

Actively collect customer feedback to gather new testimonials and refresh existing ones regularly. Encourage satisfied customers to share their experiences through reviews, surveys, or social media channels. 

To streamline the process, incorporate mechanisms for collecting feedback directly within your emails, such as clickable buttons or embedded forms.

Regularly review and update your pool of testimonials to ensure relevance and authenticity. As your products or services evolve and your customer base grows, continuously refreshing your testimonials will help keep your email content current and resonate with your audience.


According to Trustpilot, Emails with testimonials generate an average of 5 times higher engagement than emails without testimonials. Bright Local also suggests that 79% of consumers state that they trust online reviews and testimonials as much as personal recommendations, contributing to a positive brand perception.

Hence, there’s no doubt that you must include testimonials in your emails. However, you must be strategic about how you position these testimonials. If you follow the above-mentioned tips, you will most likely see more success in your email campaigns. 

Finally, if you want an easy solution to gathering testimonials and integrating them into your emails, you must try using Testimonial Donut. 

With zero to very little price, we offer an end-to-end solution for collecting, managing, and integrating your testimonials with our expansive suite of recording tools and interfaces.


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Collect, manage, share all your testimonials & Google reviews in one place. All 100% free. So bloody easy your gran can do it!

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