Originating as an online shoe and accessories retailer, JustFab now has more than 5 million subscribers in a dozen countries. Highly intelligent use of data management is the cornerstone of JustFab’s success. And one particularly important bit of data is, which tests have yielded the best results?

On both of our Retail Personalization Indexes, JustFab earned a perfect score in the email category. The brand already displayed a mastery of personalized marketing, tailoring subject lines, send times and product recommendations to individual customers. JustFab wondered how they could take personalization even further. If the body of an email reflects VIP customers’ favorite categories, would that result in even more conversions?

The short answer is, yes. Dynamic categories in email messages resulted in an 11% lift in revenue per thousand emails sent (RPM).

How JustFab Raised RPM (and Clicks, Opens and Conversions)

Everyone wears shoes, but they’re everyone’s favorite thing to buy. And even if they are, not everyone has the same style preferences. JustFab utilized Sailthru’s User Profiles, which allow marketers to tap into the complete lifetime of buyer behaviors and interests in real time, to make sure their customers’ unique preferences are highlighted.

JustFab tested their hypothesis with two emails. The first promoted shoes in the hero image and subject line, followed by recommendations of the customer’s top categories. Based on people’s individual interest scores, the second email led with the customer’s favorite category, with personalized product recommendations within that category.

In addition to the lift in RPM, the experiment was also driven by a 6% in click and open rate, and a 7% increase in conversions and clicks.

“The partnership we have with the Sailthru team enables us to continuously improve managing the expectations and reality of our personalization promise to our customers, while also making it easier to manage the internal connections needed with ecommerce, operations and customer service,” says Monica Deretich, JustFab’s VP of Marketing.

JustFab took that test even further by extending those preferred categories to email subject lines. Promoting animal print, the retailer tested two different subject lines: “Prints that ROAR!” and “Bags And More in Prints That Roar!” The personalized subject line resulted in a 19% lift in RPM, a 4.2% lift in click-to-open rate, and a 9.6% lift in conversion per click rate.

Though this sounds complicated, JustFab was able to administer these tests easily. Sailthru’s Email Composer has drag and drop capabilities with personalization included. At the same time, our capabilities also allow for subject lines to be personalized for every individual in real time based and all it takes is a small snippet of code.

Introducing the Little Black Bag

Cart abandonment was another high priority of JustFab — as it should be for every retailer. According to eMarketer research, more than three-quarters of online shopping carts remain abandoned, particularly those filled with clothes. Most marketers go the retargeting route, but JustFab tested other strategies.

JustFab cleaned up their email headers with several variations, testing to see which one really resonated with subscribers. The clear winner introduced the little black bag, a shopping bag icon with a number on it. That number represents how many items are in a shopper’s cart.

Beyond the header, JustFab revamped their cart and browse abandonment emails with streamlined messaging and improved branding. Subject lines and hero images are dynamic, changing to reflect the type of product in each individual customer’s shopping bag. If she’s got clothes and shoes in there, for example, her interest profile dictates the image. The test drove clicks in email and similarly onsite, leading to a 33% increase in click-to-open rate and a 56% increase in RPM.

During the holidays last year, JustFab even worked cart abandonment into their discount strategy. Rather than sending generic messaging about what’s on sale site-wide, JustFab sent discounts to those customers with items in their carts, capitalizing on the fact that they’d already expressed buying intent.

Though all of these tests were different, they ultimately proved the same thing: Personalization pays off.