[2026 Edition] What is Klaviyo? A comprehensive guide to the world-standard CRM tool for Shopify

Klaviyo is an e-commerce focused CRM and marketing automation tool that integrates with e-commerce platforms like Shopify to automate customer communication, primarily through email. Its main feature is its ability to import customer purchase history and browsing behavior in real-time, allowing users to design "who to send what, and when" based on data. Over 160,000 brands worldwide use Klaviyo (based on official figures at the time of writing), making it a de facto global standard for e-commerce CRM.

This article, written by Yulie, a company specializing in CRM support for Shopify x Klaviyo, provides a comprehensive overview of Klaviyo's key features, how it differs from other email marketing tools, how it can be used by Japanese e-commerce sites, and important considerations before implementation. The article is structured to provide all the necessary information for those considering Klaviyo.

What is Klaviyo? A CRM and Email Marketing Tool Specialized for E-commerce

Klaviyo is a marketing platform offered by a company founded in Boston, USA in 2012. It was originally developed as a data analysis foundation for e-commerce sites, so it is structured with "email and SMS delivery" built on top of a "system for accumulating and analyzing customer data." This origin is a key differentiator from typical email marketing tools.

Not just an "email marketing tool" but a "customer data platform + delivery functionality"

Many domestic email newsletter tools are designed to "send mass emails to a list of email addresses." Klaviyo, on the other hand, automatically links each customer's profile with behavioral data such as order history, products viewed, email open/click activity, and website visits. All of this data can be used to create segments (narrowing down recipients) and automated campaigns. For example, it's possible to easily extract granular conditions such as "people who have purchased more than twice in the past 90 days and viewed a specific category of products but did not purchase them" using only the management screen.

Designed for integration with Shopify

Klaviyo can be connected to Shopify via an official integration app, automatically syncing data such as orders, customers, products, carts, and browsing activity. In 2022, Shopify invested in Klaviyo, indicating a deep relationship between the two companies, both technologically and financially. For Shopify stores, Klaviyo can be considered a prime candidate for "the most compatible CRM tool." The specific integration steps are explained in detail in Shopify and Klaviyo Integration Method and Initial Setup Guide.

What Klaviyo Can Do: 6 Key Features

1. Segmented Delivery (Customer Filtering)

You can define target audiences by combining various data points such as purchase amount, number of purchases, last purchase date, browsing behavior, and email reactions. Segments are automatically updated in real-time, which is a major practical advantage: "once created, they always deliver to the latest target audience." Extracting high-value customers and dormant customers based on RFM analysis is also possible within the standard features.

2. Flows (Automation of Scenario-based Delivery)

This is a core feature of Klaviyo. It allows you to automatically send multi-step emails triggered by events such as "items added to cart but not purchased" or "30 days passed since the first purchase." Representative flows include:

• Welcome flow (greeting and brand introduction immediately after newsletter registration)
• Abandoned cart flow (follow-up for cart abandoners)
• Abandoned browse flow (guidance for those who viewed products but left without purchasing)
• Post-purchase flow (thank you, review request, usage instructions)
• Repeat purchase promotion flow (notifications for replenishing consumables)
• Dormant customer re-engagement flow (re-engagement for customers who haven't purchased for a certain period)

Once built, flows run automatically 24/7, making them a foundational feature for e-commerce sales. Abandoned cart flows, in particular, have a high priority for implementation, and their design points are summarized in the Abandoned Cart Email Creation Guide.

3. Campaigns (Mass mailings and newsletters)

Mass mailings such as new product announcements and sale notifications can also be carried out using segments. Features such as optimizing delivery times for each recipient and A/B testing (subject lines, content) are standard. The drag-and-drop editor allows for easy creation of Japanese emails.

4. Sign-up Forms and Pop-ups

You can create newsletter sign-up pop-ups and embedded forms within Klaviyo and display them on your Shopify store. Display conditions (number of visits, time spent, just before exit, etc.) and targets (new visitors only, etc.) can be finely controlled, and coupon integration is also possible. Registrants via the form are directly added to your list and can be connected to the welcome flow.

5. Reporting and Analytics

Not only email open and click rates, but also the revenue attribution ("how much was sold through that email") is automatically aggregated. The dashboard constantly displays the ratio of Klaviyo-driven sales to total sales, and the ability to explain the ROI of your initiatives in monetary terms is a strength not found in other delivery tools. For an idea of typical open rates, please refer to Average Open Rate for E-commerce Newsletters.

6. SMS and Mobile Push Notifications

SMS delivery is a core feature in the US, but in Japan, due to SMS delivery costs and differences in reception culture, an email-centric approach is more practical. For Japanese stores, the email features alone can achieve significant results initially.

Differences from other email marketing tools

Here's a comparison of Klaviyo with other tools commonly compared by Japanese Shopify stores.

If you just need to "send and be done," Shopify Email or domestic tools might suffice. However, if you aim to leverage customer data to increase LTV (Customer Lifetime Value), Klaviyo's scalability becomes invaluable. For a detailed comparison of each tool, please see Shopify Email App Comparison.

How Japanese Shopify Stores Can Utilize It and Expected Effects

Based on our experience supporting small and medium-sized Japanese e-commerce businesses at Yulie, it's often possible to aim for email-driven sales to account for 10-25% of total sales by optimizing Klaviyo's flows and campaigns (this is a rough estimate as it heavily depends on product type and list size). Stores with the following conditions tend to see particularly good results:

• Products with potential for repeat purchases (food, cosmetics, consumables, apparel, etc.)
• A certain number of monthly website visitors and orders, allowing for data accumulation
• An email subscriber list of several hundred or more, or the ability to create a funnel to gather one

Conversely, for products with mostly one-time purchases or newly launched stores with extremely low visitor numbers, focusing on traffic acquisition first might be more appropriate.

Klaviyo's Pricing Model

Klaviyo uses a usage-based pricing model determined by the number of "active profiles (customers eligible for delivery)." It's free for up to 250 profiles and 500 emails per month (as of writing). As your list grows, the cost increases. For estimated monthly costs based on list size and settings to reduce unnecessary expenses, please refer to Klaviyo Pricing Explained Simply.

Points to Note Before Implementation

Admin screen is in English

While email content and forms can be created in Japanese without any issues, the admin screen itself is in English. Although browser translation features can generally handle it, many users struggle with the initial setup.

Neglecting list management can lead to inflated costs

Due to the usage-based pricing, letting inactive subscribers linger for extended periods will only increase costs. Regular pruning of inactive profiles (suppression) is an essential operational task.

"Design" determines results

Klaviyo's rich feature set means that results can vary significantly depending on how you design which segments receive which flows and in what order. It's crucial to understand before implementation that simply installing the tool does not automatically guarantee increased sales.

Frequently Asked Questions

Q. Can Klaviyo send emails in Japanese?

Yes, it can. Email content, subject lines, and forms can all be created in Japanese. Japanese fonts are also supported by common email clients. Only the administration screen is in English.

Q. Can it be used with shopping carts other than Shopify?

Yes, it can. There are official integrations with WooCommerce and BigCommerce, and technically, integration with domestic carts like ecforce is possible using the API. However, in terms of ease of integration and depth of data, the combination with Shopify is the most powerful.

Q. Can I start using it for free?

There is a free plan for up to 250 profiles and 500 emails per month (as of writing). For small lists, you can try out the main features for free, so we recommend starting with the free plan to experience integration and flow building before upgrading to a paid plan.

Q. How long does it take to see results after implementation?

Abandoned cart flows and welcome flows start running automatically from the day they are launched, so "email-driven sales" may start being measured within a few days. However, to reach a stable level of results, it's realistic to expect 2-3 months, including list growth and flow optimization (as a guideline).

Yulie is a CRM operations support team specializing in Shopify x Klaviyo. As a Klaviyo Certified Partner, we provide end-to-end support for small and medium-sized e-commerce businesses in Japan, from flow design to email creation and operation improvement. If you'd like to "learn about suitable designs for your business" or "have implemented it but aren't utilizing it effectively," please feel free to contact us for a free consultation.