Resources Hub » Blog » 15 of the Best Testimonial Email Subject Lines

Arguably the most important part of any email, your subject line serves as your first impression and could be the difference between a click or the trash bin.

While many marketers disregard subject lines as an afterthought, it’s important to carefully craft subject lines, so readers explore your message further and connect with your brand.

With the average person receiving 120 emails a day, it can be difficult to cut through the noise.

Between daily promotions, newsletters, and your mother wondering why you haven’t called her yet, it can be overwhelming when scrolling through your inbox.

As an email marketer, you don’t want your emails to end in the trash bin, so developing eye-catching and descriptive subject lines is crucial.

With the right subject lines and content, you have the ability to increase your email engagement rates and convert prospective leads.

What types of emails will appeal to your audience? Read on to discover more about testimonial email subject lines as a way to harness your subscriber’s attention, as well as a few examples we’re excited about.

What is a testimonial?

If you’re scratching your head wondering why you’d send a testimonial email, hear us out.

Testimonials are proclamations from your customers that certify the value of your brand’s products or services. Ninety-five percent of customers read reviews before making a purchase decision online.

Those reviews are unsolicited, meaning you have customers who are willing to describe your business as effective and reliable, which influences tens or hundreds of other potential customers. Powerful, right?

It’s important to note that there are two types of testimonials you can use:

  • Endorsement testimonials: given by a well-known influencer who announces their support for a brand publicly
  • Customer testimonials: given from an actual customer, most likely unknown to your subscriber list

While endorsements are well known, they’re also paid and may not appear as genuine. Customer testimonials offer a more personal experience about what your brand has to offer.

You can receive testimonials from a number of digital and face-to-face landscapes, such as:

  • Social media posts and reviews
  • Case studies
  • Video interviews
  • Blog post reviews
  • Interviews
  • Press reviews
  • Peer reviews (Yelp, Amazon, etc.)

Why are testimonials effective content for your emails?

Testimonials help convince subscribers that your services are valuable and credible, and therefore make excellent content for your marketing strategy. While testimonials are oftentimes buried at the bottom copy of your email, making them a focal point of your email is a smart move to build your brand’s social proof and increase engagement.

Why? Effective testimonials can help increase your conversion rates. As user-generated content and viewed as a third-party endorsement, testimonials create more trust and build a bandwagon effect with other subscribers.

It’s psychology. Products and services recommended by others are seen as “better” than those without proof, and people want in on that action. In fact, 84% of people say they trust consumer reviews as much as a recommendation from a friend.

Bottom line: the right testimonials can build your brand recognition and earn new customers.

Start asking your customers for testimonials.

Now that you know the importance of testimonials for your brand, you need to start collecting them. While some testimonials like reviews on Yelp or Amazon will be posted organically, you’ll have to openly ask your clients for reviews as well.

By utilizing email marketing, you can send out automated communications to remind your clients to leave testimonials. Here are a few tips to get started:

  • Ask immediately: You want your service or product to be fresh in your customer’s mind, so a timely response is crucial to get an honest response.
  • Follow a customer journey: As part of lead flow, asking for testimonials throughout many points of the customer journey helps receive different perspectives of your brand.
  • Make it easy: Create a process that takes the pressure off from your customers to give the “perfect” review with an easy email or form.
  • Follow up: No matter if the review is positive or negative, it’s important to follow up to show that you care about your customer’s experience.

 TradeGecko Sends Testimonial Request

Source: Really Good Emails

We love this email from TradeGecko for a few reasons. The subject line “Could you please help us with GetApp?” is urgent while still sounding conversational. Once opened, the email itself is simple to read, includes why reviews are beneficial and connects directly to a review platform.

How to create the best subject lines

Before diving into examples of testimonial email subject lines, it’s important to understand how to write one. By knowing the fundamentals, you’ll be able to easily craft eye-catching email subject lines to convince your subscribers to click.

  • Know your audience: Who are you trying to reach with your testimonial? Your language needs to connect with them.
  • Utilize technology: If you’re brushing up on your writing skills, there are many tools available that will help you improve open rates like CoSchedule’s Subject Line Tester.
  • A/B test: Try different variations of subject lines to test which your audience responds to better.
  • Keep it short: Develop copy that’s five words or less, so it appears correctly on mobile devices.
  • Use personalization: Include the subscriber’s name or location for a personalized touch.
  • Drop title case: Using sentence case promotes a more conversational tone.
  • Fear of missing out: Elicit FOMO to create a sense of urgency.
  • Use numbers: Use a specific discount, statistic, or numerical benefit.

Writing a successful subject line may take trial and error to understand what speaks to your audience and gets results.

15 testimonial email subject line examples

Ready to start collecting testimonials to showcase your brand’s products and services? Once you begin building a bank of responses, you can start utilizing testimonial subject lines to see your open rates increase.

You can take advantage of your subscriber base by both asking and sending testimonials. However, it’s important to clearly identify which subject lines are for what purpose to avoid creating confusion. Take these examples:

Testimonial subject line

  • Here’s what Nashville’s CEOs said about us
  • It’s crazy how much love we’ve gotten!
  • Jen wore it, grab it before anyone else does!
  • USA Today has a few kind words
  • The reaction to our new product has been…
  • More athletes prefer our brand
  • See top travel destinations

Casper uses email to ask for reviews.

Source: Really Good Emails

With a subject line “Did you forget something?” Casper utilizes an abandoned cart email as a way to display a testimonial from another customer. An effective tactic, the customer is able to read about what they’re missing by not purchasing the product and has an opportunity to read more reviews for further validation.

Bose uses testimonials in a Black Friday email.

Source: Really Good Emails

The subject line of this Bose email reads “Save up to 50% on speakers and headphones: Black Friday is here.” While not a typical testimonial email subject line, the email contains testimonials that offer social proof to the customer who may be on the fence about participating in Black Friday.

Testimonial request subject lines

  • [Customer Name], did we earn your trust?
  • [Customer Name], do you agree?
  • You know us. What do you think?
  • [Customer Name], thank you…
  • Please don’t say goodbye
  • Did you like [product name]?
  • We need you…
  • This link is expiring

Airbnb asks for reviews after stays.

Source: Really Good Emails

After using the Airbnb service, the company sends an email asking for a review with the subject line “Write a review for [Sellers Name].” This email subject line is effective because it’s to the point and sets clear expectations. The customer knows what this email contains before it’s opened and hopefully had a positive experience at the stay to leave a positive testimonial.

Thompson Chicago Hotel requests a survey.

Source: Really Good Emails

The Thompson Chicago Hotel uses the subject line “Thank You for Your Recent Stay” to request a survey testimonial from recent guests. The CTA leads to a form that asks specific questions to help guide the customer in providing an honest review.

Wrap up

If you’re looking for new ways to increase your engagement rate, updating your subject lines could be the answer. The right subject line entices your subscribers to open, read, and hopefully take action from your email. Testimonials are a great way to boost your email content with credibility and social proof from past customers to persuade perspectives into your customer journey.

To create a successful testimonial subject line, you need to:

  • Develop subject lines to request and contain testimonials
  • Ask for testimonials immediately after the customer interacts with your service or product
  • A/B test different versions of your subject line and measure performance
  • Get to the point and set proper expectations

Ready to write your own testimonial subject lines? Campaign Monitor offers a comprehensive platform for all your email marketing needs to target your audience. Try it for free today!

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This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.
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