Optimized Email: The Core Of Digital Marketing

According to a new research report from Retention Science, to determine the key shared attributes of the best-performing emails in search of the “perfect” marketing email, eMail marketing generated the highest ROI for eCommerce in 2014, and consistently outperforms other channels in engagement and conversion.

Although flashier channels like social media and mobile marketing routinely steal headlines, email is still the core of every effective digital marketing strategy, says the report. The reason is simple: it works. Even tech-savvy Millennials prefer to communicate with brands through email; 47% of respondents chose email as the preferred channel, while only 6% selected social media.

The question is no longer whether companies should invest in email, says the report, but rather how to maximize on its return. Consumers are inundated with marketing messaging at all hours of the day, and it’s easy to get lost in the noise. Strategic email messages must be optimized to convert.

Dollar-off savings may seem like the most appealing promotions, but they’re not as effective as other types of deals, the report says. The study data shows customers are more receptive to percent-off deals with 38% of customers more likely to click, and 47% more likely to convert when they were presented with a percent-off offer vs. a dollar-off offer

Subject lines that mention novelty items generate more interest, showing a 6% lift in open rates. However, when it comes to featuring products in the email body, common goods such as groceries and personal basics have a 10% higher click-through rate than novelty or specialty items, even when the novelty item was featured in the subject line, says the report.

Novelty items are good at catching the eye because customers want to stay on top of perceived deals on big-ticket or specialty items, but most people don’t tend to purchase unless there is a specific need. Basics, on the other hand, need replenishing on a more regular basis.

And, the study finds that punctuation impacts email open rates. The presence of any type of punctuation mark increased open rates by 9%. Question marks are particularly effective at engaging recipients. In fact, the study found subject lines with question marks have open rates 44% greater than those with exclamation points, says the report.

Six to 10 words is still the optimal length for email subject lines, says the report, ranking highest for open rates (21%) for the second year in a row. Second highest is zero to five words, with a 16% open rate. The rates start to fall significantly in the 11 to 15-word range, with emails only opened 14% of the time, and results only decrease from that point.

Email Opens By Subject Line Lengths


Open Rate

1-2 words








Source: Retention Science, November 2015

Jerry Jao, CEO of Retention Science, says “… consumers are sifting through tons of emails a day and making at-a-glance judgments about which to open… so it’s vital to be descriptive and brief… six to 10 words is the sweet spot, says the report.

Losing access to a customer’s inbox can be detrimental for marketers, In looking at the unsubscribe data over the course of a year, the study found that 28% of total unsubscribes occurred in August, the highest of any month.

While open rates are consistent throughout the year, click rates are highest at the beginning of the holiday season, reaching 30% in October and 27% in November. Likely due to Fourth of July holiday sales, July has the best conversion rate of any month, with rates 21% higher than average. December ranks second, with rates 10% above the norm. 

The report concludes by saying that there is, of course, no single email format that will magically convert 100% of the time. The truly perfect marketing email is achieved through personalization, where each customer receives content and offers that have been optimized to their unique preferences.

For additional information from Retention Science, please visit here.


2 comments about "Optimized Email: The Core Of Digital Marketing".
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  1. Julie McDermott from Shelter Insurance, November 18, 2015 at 10:09 a.m.

    The data in your chart about subject line length doesn't match what's in the paragraph above it. Which is accurate?

  2. Don Sturgill from, November 22, 2015 at 11:46 p.m.

    Ditto on Julie's remark. Check that box... it's wonky :)

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