Outshine the Holiday Inbox Crowd With These Subject Line Strategies

During the 2014 peak holiday season, consumers received roughly 50 percent more promotional email than they saw earlier in the year. I expect to see a similar increase when we look at email for the 2015 holidays, making it even harder for email marketers to stand out in the inbox. Well-crafted subject lines can help to break through the clutter and grab readers’ attention.

I analyzed key phrases in a random sample of approximately 10,000 subject lines, categorized by topics or themes, to see what’s working in 2015. One pattern stood out as I examined correlations between subject line groups and read rate lifts or dips vs. the norm: frequently used phrases rarely delivered better-than-average read rates.

Some of the highest-performing subject line phrases fell into this category, which included references to prizes, bonuses and other incentives that weren’t merchandise discounts. The phrases “reward offered,” [number of] “points,” and “claim now” correlated to significantly higher read rates than the overall average. However, on the whole, subject lines in this category either flatlined (no lift) or had a lower-than-average performance.

Subscribers particularly ignored offers of “freebies” and “free samples,” possibly because of their skepticism. Subject lines offering loyalty points saw decidedly mixed results, possibly reflecting consumer satisfaction with individual programs. Offering bonus points can backfire if they don’t inspire better read rates. Frequently giving away points can signal that they aren’t especially valuable or customers may not understand how to apply the points or use the loyalty program.

It’s no surprise that this category, which included price and shipping discounts, contained a large portion of the messages we analyzed—almost 25 percent. “Lowest price,” “big savings,” “shipping sitewide,” and “sitewide sale” correlated to slightly higher read rates than the others in this category. Shipping-based subject lines were common, and “free shipping” references far surpassed any other subject line phrase in terms of frequency. However, this didn’t coincide with any statistically significant change in read rate. Perhaps the popularity of free shipping makes it hard for this message to stand out, especially as consumers demand it as a standard part of doing business online.

Subject lines that create urgency by issuing deadlines and promoting scarcity are still a popular way for marketers to engage subscribers, accounting for 30 percent of all subject lines in our sample. But does encouraging readers to shop during the “final hours” of a sale really get their attention more effectively than other approaches? According to our correlations, no. For example, the phrase “last chance,” which made up more than 3 percent of all the subject lines we analyzed, yielded no lift at all over normal read rates. Similar to “free shipping,” the high frequency may create a commonality that dilutes the power of urgency. This may highlight the danger of copying successful marketing tactics from other brands. If you don’t test how your own audience will respond, you could be merely foregoing your chance to differentiate your message from theirs.

Exclusive offerings
Consumer skepticism may partly explain this category’s middling overall performance, as subject lines referring to exclusive deals or restricted offers didn’t distinguish themselves from others’ ability to engage readers. “Friends and family” was the most commonly used phrase in this category, accounting for 20 percent of “exclusive” subject lines. This phrase correlated to below-average read rates. Perhaps consumers have become wary of claims of exclusivity.

Almost 30 percent of the sample promoted specific content or offered contextual guidance about the message, including teasing editorial, naming products or brands, or referring to curation such as best-sellers. While this group is incredibly diverse (religion- and spirituality-themed phrases generated the highest-performing subject lines), we did find two patterns that correlated to above-average read rates. Consumers were more engaged with subject lines that featured product names and brand names (Apple and Nissan were standouts), and they read about trending and new products in general. Phrases like “best-sellers,” “introducing the new,” and “new season” all saw significant lifts in read rates. The lowest performers in this category referred to loans, credit cards, and life insurance.

When determining a strategy for developing effective subject lines, looking at historically high-performing phrases is a logical place to start, of course. These findings suggest that there are categories and specific phrases that correlate with stronger marketing performance. However, they also point to the danger of following the traditional and popular route by simply mimicking high-performing subject lines. Doing so without testing may put your campaign at risk. The best way to reduce this risk and connect with subscribers is to continually refine your subject line strategy by segments, categories, themes, and specific phrases.

This article originally appeared on Total Retail.

minute read

Popular stories



BriteVerify email verification ensures that an email address actually exists in real-time


The #1 global data quality tool used by thousands of Salesforce admins


Insights and deliverability guidance from the only all-in-one email marketing solution

GridBuddy Cloud

Transform how you interact with your data through the versatility of grids.

Return Path

World-class deliverability applications to optimize email marketing programs

Trust Assessments

A revolutionary new solution for assessing Salesforce data quality


Validity for Email

Increase inbox placement and maximize subscriber reach with clean and actionable data

Validity for Data Management

Simplify data management with solutions that improve data quality and increase CRM adoption

Validity for Sales Productivity

Give your sales team back hours per day with tools designed to increase productivity and mitigate pipeline risks in real-time