Fit for success: Stronger uses Klaviyo to drive 21% of revenue

Industry: Apparel and accessoriesPlatform: Centra
Two women wearing brightly coloured Stronger activewear

Stronger is a global sportswear brand that aims to inspire women to live a healthier lifestyle. After bursting onto the scene in 2013 the Swedish brand has grown to become a leading name in the global fitness and leisure market. Known for its stylish leggings, sports bras and tops, the label’s playful prints are all over Instagram. But it’s not just eye-catching designs that have made Stronger a success. The company has a reputation for sustainability, using recycled polyester in products and donating a portion of its sales to rainforest conservation.


revenue attributed to email


click rate for welcome email series


conversion rate for abandoned browse flow

Learn how the activewear brand supercharged its international growth by integrating Klaviyo with Centra


Instagram and influencer marketing fuelled rapid growth of Stronger’s subscriber base. Initially, the brand’s email newsletter was an effective sales tool but its generic content quickly caused a drop in email engagement. With no marketing automation in place, Stronger was losing countless opportunities to convert sales. It couldn’t connect with consumers at key moments in the customer journey – by sending friendly abandoned cart reminders, for instance. 

The marketing team found creating cross-sell campaigns particularly irksome. The data had to be crunched manually. This was a laborious process but these campaigns were essential to avoid having excess stock of the ‘unpopular’ half of matching sets. 

And, with over half of the brand’s sales coming from outside Sweden, there was a growing need for multi-language CRM.


In search of a robust ecommerce tech stack to support international hypergrowth, Stronger adopted Klaviyo and switched its ecommerce platform to Centra.  

Centra supports multiple languages, currencies and prices, which enables the business to sell to consumers in 100+ markets. The platform’s integration with Klaviyo means that all historical and real-time subscriber data collected on the site – including their country and preferred language – is passed to Klaviyo. It allows Stronger to build segments according to subscribers’ purchase behaviour, interests and location.

By creating highly-personalised customer journeys with unique flows for each market, we’ve increased email engagement and extended the customer lifetime value.
Zelia Webster
Head of CRM, Stronger

Since supercharging its website and automation platform, Stronger has expanded its marketing ecosystem to include other services. Now, the brand has a loyalty programme with Yotpo, a streamlined customer feedback process with Trustpilot, and trackable shipping in several countries. Thanks to Klaviyo’s easy integrations with these tools, set-up was swift and smooth.

We’ve integrated lots of services into our tech stack. What’s fantastic is that all the related customer communications are managed through Klaviyo – whether they’re about loyalty points or shipping. Everything’s in one place. 
Zelia Webster
Head of CRM, Stronger


One of Stronger’s marketing goals is to drive more repeat purchases through targeted cross-selling. The brand uses the subscriber data in Klaviyo to understand what kind of activewear shoppers are interested in: bold patterns, the seamless range, plain black? Everyone’s different! Stronger translates this insight into segments and sends customers post-purchase flows that are highly specific. 

One flow promotes bra tops to women who have bought only leggings. The brand set this up when it observed that people tend to buy leggings first, and then might add a top later, when they’re feeling a bit braver.

With Klaviyo you can be so granular. If someone buys a pair of tights we can send them a specific email with tips on how to care for the tights, along with suggestions for tops we think they’ll love. Having that high degree of personalisation is so powerful.
Zelia Webster
Head of CRM, Stronger

To boost email engagement in its biggest markets, Stronger has localised the key email flows. This seems to be working. The welcome series has 20 country segments and achieves a high 19% click rate. The abandoned cart flow recovers 10% of shopping carts, which is more than twice the average for the sector

Another of Stronger’s goals is to drive sales of its new seamless range. The brand uses Klaviyo’s abandoned browse flow to send a product guide to subscribers who’ve been looking at the comfy leggings. The creative newsletter-style email explores their fit, fabric and suitability for different activities. It works brilliantly, converting 6.8% – 8x higher than the average for this flow

Stronger also runs its transactional email notifications through Klaviyo. Although these don’t have a ‘hard sell’ message, the order confirmations and shipping notices drive a significant volume of sales. It just goes to show that a well-timed, nicely-branded email reminder can sometimes be enough to motivate customers to buy again.

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