How to Collect Reviews for E-Commerce Sites | 3 Reasons Why Reviews Aren't Coming In and How to Fix It

[Updated September 2026] “I’m sending review request emails, but hardly any reviews are being posted”—this is one of the most common concerns we hear from e-commerce site operators. Customer reviews are a valuable information asset for selling products, but while more and more e-commerce businesses are focusing on collecting reviews, many still report low collection rates as a challenge.

In this article, we’ll explain the three reasons why reviews aren’t being collected and how to address them. We’ll also outline practical steps—including “when to send requests,” “what kind of email to send,” “a submission process that can be completed entirely on a smartphone,” and “how to measure collection rates”—along with U-KOMI’s features.

Three Reasons Why Reviews Aren’t Coming In

—Reason 1: You Aren’t Sending Review Request Emails

From the customer’s perspective, the transaction is complete once the product arrives. Few customers will voluntarily revisit the site to write a review, especially if the e-commerce business takes no action.

This is where review request emails are effective. Sending a request email after shipping the product reminds customers to leave a review. If they’re satisfied with the product, they’re more likely to post one.

—Reason 2: You Haven’t Offered Incentives

Incentives are a major motivator for submitting reviews. According to a survey by one of our partners (*1), 56.9% of customers cited the expectation of receiving a benefit as their motivation for writing a review. Offering coupons or points and clearly stating this in the request email tends to make it easier to collect reviews.

Incentives not only boost the response rate but also lead to repeat purchases of the reviewed product and purchases of other items. By using tools that automatically issue coupons or award points, you can manage this process without increasing the workload on your staff.

*1 SUIHEISEN (2024), “A Must-Read for E-Commerce Operators and Sales Agents! Image Survey on Customer Feedback and Reviews on Online Shopping Sites”

—Reason 3: Posting Reviews Is Too Time-Consuming

“Logging in, finding the product page, and filling out the form”—this hassle is the biggest reason people hesitate to post reviews. Especially on smartphones, the more page transitions there are, the more likely users are to abandon the process.

The key to increasing the response rate is to combine text reviews with star ratings and multiple-choice questions (surveys) so that users can submit a review simply by “answering a few questions,” and to provide a direct submission path from email without requiring additional page transitions.

Practical Step 1: “When” to Request Reviews

The timing of the request email is the most critical factor in determining the response rate.

• The general rule is “after the product arrives and the customer has started using it.” Sending the request immediately after shipment is too early—the product hasn’t arrived yet—while waiting too long allows memories of the purchase experience to fade.
• The optimal timing varies by product category. For apparel and general merchandise, aim for a few days to one week after arrival; for products like cosmetics and supplements—where it takes time to notice the effects—aim for two to four weeks later.
• Limit reminders to one or two. Sending too many requests can damage your brand image.

With U-KOMI, you can configure the system to automatically send a request email “X days” after the order date.Emails are sent automatically every day, and you can adjust the number of reminders sent after the first request (up to 3 per request) and the maximum number of emails per order (up to 5) from the admin panel. With the Enterprise Plan, you can also set delivery timings on a per-product basis.

Practical Step 2: Sample Text for Request Emails

In the subject line, clearly state “what you want the recipient to do” and “the benefits”; keep the body brief. Structure the email so the recipient can click the “Post” button immediately.

There are three key points.

• Include the product name (so it’s clear at a glance what the review is about)
• Make it clear how easy it is—use phrases like “in just 1 minute” or “directly from this email”
• Convey your commitment to using customer feedback for improvement (so customers feel their reviews matter)

With U-KOMI, you can freely edit the request email template to match your brand’s tone, and you can even change the sender’s email address to your own domain to boost open rates. By adding unique questions (custom questions) for each product, the request email becomes a survey in itself. For more tips on using custom questions, check out this article:
The Secret to Boosting Sales Through Survey Collection!

Practical Step 3: Create a Review Submission Process That Can Be Completed Entirely on a Smartphone

Nowadays, most e-commerce purchases and review submissions are made on smartphones. With a process like “Open email → Navigate to an external page → Log in → Fill out a form,” it’s inevitable that users will drop off along the way.

U-KOMI’s “In-Email Review Submission” feature allows customers to complete their review submission without ever leaving their inbox. Since they can simply tap the star rating in the email, type their review directly in the body, and submit it, this minimizes the effort required and leads to higher submission rates.

Providing additional submission channels beyond email further reduces the risk of missed reviews.

• Review Requests via LINE: Request reviews via LINE, which has a higher open rate than email. You can send these requests by integrating with your official LINE account. For more details, see “What Is the U-KOMI LINE Integration Feature?”
• Submission via QR Code: Include a QR code in product packaging or at physical stores so customers can scan it with their smartphones and submit a review directly.
• Generating Review Request URLs: Direct customers to the submission page via any channel, such as email newsletters or social media direct messages.

Practical Step 4: Measure Your Review Collection Rate

Improvement begins with measurement. The review collection rate is generally defined as follows:

Review Collection Rate = Number of reviews submitted ÷ Number of review requests sent (or number of orders)

Additionally, by examining the open rate and click-through rate of your request emails, you can identify where users are dropping off. If the open rate is low, the subject line or timing of the email may be the issue; if the click-through rate is low, the body text or incentives may need improvement; and if the post rate after clicking is low, the submission form may be too cumbersome.

In the U-KOMI admin panel, you can view email analytics data, including the number of emails sent, open rates, click-through rates, and the conversion rate (CVR) for reviews submitted via email. For requests sent via LINE, you can similarly track the number of messages sent, the number of reviews acquired, and the acquisition rate.

As a benchmark for collection rates, case studies of companies using U-KOMI show that Kyoden Co., Ltd. achieved a review acquisition rate of over 30%, while Ed-Inter Co., Ltd. increased its review acquisition rate by 1.5 times after implementation.

Case Study: From a few reviews per month to about 300 per month—just by changing the call-to-action

Kinari Co., Ltd., a natural cosmetics brand, previously received only a few reviews per month even when requesting reviews via company emails that included a 500-yen coupon.After implementing U-KOMI, approximately 300 reviews are now posted each month without any offers, and the review collection rate has increased by 3,600%. The company explains, “Previously, customers had to log in to their My Page to submit a review, but with U-KOMI, they can post reviews directly from the email—that’s the main reason.”

Read Kinaru Co., Ltd.’s case study

For another success story of improving from a situation where no reviews were being collected at all, please see the case study of Kaburamu-an Co., Ltd.

Summary: Review Collection Depends on “Post-Purchase Design”

In most cases, the reason reviews aren’t coming in isn’t due to a lack of customer motivation, but rather to operational design issues—specifically, the timing of the request, the incentives provided, and the effort required to post a review.

• Automatically send a request email after the product arrives, around the time the customer starts using it
• Offer incentives such as coupons or points, and clearly state them in the email
• Create a seamless submission process via the email, LINE, or QR code so customers can post directly from their smartphones without leaving the app
• Monitor the number of emails sent, open rates, click-through rates, and conversion rates monthly, and address any bottlenecks

U-KOMI is a UGC tool that automates all these measures from a single dashboard.It provides a comprehensive suite of features necessary for collecting reviews, including automated review request emails, in-email review submission, requests via LINE and QR codes, automatic awarding of coupons and points, and analytics data. It is compatible with major shopping cart platforms such as Shopify, makeshop, and Color Me Shop, and the setup procedures are explained in the Shopify Guide and the makeshop Guide.

If you’d like to review review collection methods, U-KOMI’s features, implementation case studies, and pricing all at once, please download our service brochure.

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View a list of UGC use cases here: https://u-komi.com/jirei

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