A/B Test Results: Personalizing Email Subject Lines

Email marketing is one of the most effective way to engage and convert customers continuously. However, with today’s hyper-connected consumer, retail brands need to push and shove to get customer’s attention when the next phone alert quickly distracts them. In fact, 92% of shoppers say they are doing other things while shopping. This is why it is so important to craft email subject lines that drive interest to open. I would argue - crafting a compelling subject line has become one of the most crucial factors to driving engagement.

You’ve probably heard quite a lot about the importance of email personalization, but is it really that important for the subject line? We put it to the ultimate test — the A/B test — with several customers to find out what subject lines work best for different behavioral email campaigns.

Cart Abandonment: Referencing the Shopping Cart
The test: Over seven days, a top retail brand just shy of the Fortune 500 list, ran an A/B subject line test for two abandonment drips with (A) as a generic subject line and (B) referencing the cart that was abandoned.

A. “Forget Something?”
B. “You left something in your shopping bag!”

The winner: B - Referencing a customer’s shopping bag had a 5% higher open-rate than a generic reminder.

About the campaign: Cart abandonment campaigns reminded the customer they abandoned a cart before purchasing. This campaign used timing and critical offers to convert them before it was too late. Check out the Smarter Spotlight: Cart Abandonment for more key strategies.

Browse Abandonment: Including Specific Product Names
The test: The same retailer also tested whether including the product name in a browse abandonment campaign impacted email engagement.

A. "{Product Name} is going to look great on you!"
B. "You’re going to love it!"

The winner: A - Product-specific subject lines increased open rates by 5%.

About the campaign: Browse abandonment triggers remind customers in real-time about the product or category previously viewed to nudge customers back to your brand’s website or in-store location to complete the purchase. Learn more strategies and tactics for browse abandonment here.

Sale Mop-Up: Including Customer Shopping Behaviors
The test: An upscale handbag retailer ran multiple sale mop-ups targeting shoppers who browsed or abandoned carts during a sale event. The brand wanted to know if personalized subject lines including specific shopping behaviors would impact open rates.

A. “Up to 75% off styles you browsed” Or “Up to 75% off everything in your cart”
B. “Up to 75% off! Don’t miss out!”

The winner: A - Including specific shopping behaviors increased email open rates by 4%.

About the campaign: Sale mop-ups are email campaigns in partnership with sale or promotion designed to create a sense of urgency for consumers to come back to your website and purchase items they browsed heavily, carted multiple times, or carted and abandoned previously. Learn more about sale mop-ups here.

Product Replenishment: Reference Products Purchased
The test: A large retailer consistently runs multiple replenishment email campaigns to identify shoppers who purchased different items over a relative period of time. The brand wanted to determine if adding specific product categories in the subject line impacted email open rates.

A. “Your Underwear Drawer Called. It Wants a Refresh”
B. “It’s Time for an Update”

The winner: A - It worked! Referencing specific product categories in subject lines they saw a 6% increase in email open rates.

About the campaign: Product replenishment campaigns remind shoppers when it’s time to buy more of a product they previously purchased. These campaigns work best for items that should be replaced after a certain amount of time. 

Seventy-four percent of millennials are frustrated when they receive too many marketing emails from brands. It’s crucial to create engagement in customer inboxes right away, or your brand’s email will be found in the trash...again. Want to learn more about how to turn up your email performance? Check out “When is the best time to send cart abandonment emails” or our Ecommerce Behavioral Marketing Playbook.


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