Reviews and customer photos in email: where they earn their spot

Why put reviews in email at all?

Because reviews move people who are on the fence. The Spiegel Research Center at Northwestern found that "the purchase likelihood for a product with five reviews is 270% greater than the purchase likelihood of a product with no reviews," and for a higher-priced product, conversion rose 380%. That research is from 2017, but the pattern holds up in newer surveys. PowerReviews surveyed 15,870 US shoppers in December 2023 and found 91% said they were more likely to buy a product with reviews that include photos and videos.

Neither study measured email specifically. I couldn't find a credible, independent stat on UGC inside email, only vendor case studies. So treat this as a reason to test, not a promised lift.

Which emails should get reviews?

Abandoned checkout and cart

This is the strongest spot. Someone got all the way to checkout and stopped. Often that's doubt: will it work, will I like it, is it worth it. A review of the exact product they left answers that better than a discount.

Abandonment emails are also where I like to test first, because that's where you learn what gets people across the finish line when they're close to buying. Try a version with a review against one without. More on the flow itself in abandoned checkout emails.

Browse abandonment

Lighter intent, same idea. They looked at a product and left. A short review under the product image gives them a reason to look again. See browse abandonment emails.

The welcome series, non-customer side

New subscribers who haven't bought don't know you yet. A review or customer photo in email #1 or #2 shows them real people use the product. Keep it to one or two, near the offer. The full build is in welcome email series.

Product launches

A brand-new product has no reviews, but your existing best sellers do. Mention what customers already say about the line, or follow the launch a few weeks later with the first reviews of the new product. More in product launch emails.

Where they matter less

Repeat customers already know the product. In reorder reminders and VIP emails, a review is fine but not the main event. Spend that space on what's next for them.

Star rating, one quote or a customer photo?

Each does a different job:

• Star rating and review count under a product: quick social proof, best in product grids.
• One short quote: the strongest for abandonment emails, especially if it answers a common objection ("I have sensitive skin and this didn't irritate it").
• A customer photo: shows the product in a real home or on a real person. Great in welcome and launch emails, if you have permission.

Pick the review that answers the doubt, not the most glowing one. Spiegel found purchase likelihood "typically peaks at ratings in the 4.0 – 4.7 range" and starts to drop as ratings approach a perfect 5.0. A believable 4.6 beats a suspicious wall of perfect scores.

How do I get reviews into Klaviyo emails?

If you use Klaviyo Reviews

Klaviyo has a Review quote block. A static block shows "the same featured review to everyone." A dynamic block is "available only in event-triggered flow emails with product information" and Klaviyo says it's supported in event-triggered flows, back in stock, low inventory and price drop flows. So an abandoned checkout email can show a review of the product the person actually left.

A few limits worth knowing: the block "can only display reviews submitted by a verified purchaser," and by default only 5-star reviews show in the picker, though you can change that filter. Klaviyo can also show star ratings inside product blocks, and if a product has no rating, the stars just don't appear.

If you use another review app

Most of the big ones send data into Klaviyo, but showing review content inside an email usually takes more setup:

• Okendo sends events like "Created Okendo Review," including the rating, review text and image links. Displaying reviews in emails uses a web feed, available on its Power plan and above.
• Yotpo sends events like "Yotpo Review Created" and supports putting review highlights in emails through a web feed on its Pro, Premium and Enterprise plans.
• Stamped sends events such as positive, negative and photo review submissions, and needs a paid plan. Reviews can be shown through a web feed.
• Junip and Judge.me both integrate with Klaviyo too. Check their docs for what each plan includes.

The simple version: if your app can't feed reviews into a dynamic block, hand-pick a few strong reviews per hero product and add them as static text. That still beats nothing.

And keep asking for reviews in the first place. That's covered in review request emails.

What rules apply to using reviews and photos?

This is general information, not legal advice.

• No fake reviews. The FTC's 2024 rule "prohibits businesses from creating or selling" fake reviews or testimonials, and lets the agency seek civil penalties against knowing violators.
• Don't misrepresent what you show. The same rule bars implying your displayed reviews are all or most of them when you've suppressed reviews based on their rating.
• Don't buy positive reviews. The FTC's Endorsement Guides say "You can't condition an incentive – for example, a discount – on a review being positive." And asking only the customers you expect to be happy "would be misleading."
• Featuring real reviews is fine. The FTC says you can ask customers about their experiences and feature their comments in your ads.
• Ask before using photos. A customer uploading a photo to your review app doesn't automatically give you the right to use it in a marketing email. Get clear permission, and if your review app has a consent checkbox for photos, use it.

What do brands get wrong?

• Showing the same generic five-star review in every email, no matter the product.
• Burying the review under the footer where nobody scrolls.
• Using only perfect scores, which reads as fake.
• Pulling customer photos without asking.
• Adding reviews to every email, so they stop standing out.

What should I add first?

Pick your best-selling product, find the review that best answers the most common reason people don't buy it, and add it to your abandoned checkout email right under the product. Then test that email against the version without it.

FAQ

WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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