3 minute read

A/B Test Results: Personalizing Email Subject Lines

Email marketing is one of the most effective tools to engage and convert customers. However, with today’s hyper-connected consumer, retail brands need to push and shove to get customers' attention. In fact, 92% of shoppers say they are doing other things while online shopping! This is why it is so important to write email subject lines that drive interest to open. I would argue that crafting a compelling subject line has become the most crucial factor to drive engagement.

You’ve probably heard 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 cart abandonment email drips comparing a generic subject line (A) and one that referenced the cart that was abandoned (B).

A. Forget Something?

B. You left something in your shopping bag!

The Winner: B - Referencing a shopper’s cart saw a 5% higher open rate compared to the generic reminder.

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

Browse Abandonment: Including Specific Product Names

The Test: The same retailer as above 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 - The product-specific subject line saw open rates increase by over 5%.

About the Campaign: Browse abandonment triggers remind customers in real time about the product or category they previously viewed to nudge customers back towards the brand’s website to complete their 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-up campaigns targeting shoppers who browsed products during a sale event. The brand wanted to know if personalized subject lines that included the shopper's specific behavior would impact open rates.

A. Up to 75% off styles you browsed

B. Up to 75% off! Don’t miss out!

The Winner: A - Including the shopper's specific behavior increased email open rates by 4%.

About the Campaign: Sale mop-up email campaigns work in partnership with a sale or promotion. These sends are designed to create a sense of urgency for consumers to purchase the items they heavily browsed, carted, or 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 the subject line increased the open rate by 6%.

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 or refilled after a certain amount of time.

For additional tips for writing and executing smarter email subject lines, check out this in-depth post on subject line tools and these email design tricks.