All marketing messages, but particularly email headlines, should be punchy and informative to quickly give readers information.

There are plenty of ways for marketers to optimize promotional emails, but some are statistically better than others. Marketing Land recently reported Retention Science will soon publish the results of a study performed on email subject lines and the factors that affect how likely recipients are to open email marketing materials. It gave a sneak peek of the results and one of the most striking attributes of opened mail is subject line length. 

The text customers see in their inboxes should be descriptive and appealing, but also short and sweet. The highest open rates (21 percent) came from emails with 6- to 10-word subject lines. Five or fewer words only got customers to click emails 16 percent of the time, and subject lines with 20 or more words were only opened 8 percent of the time.

What gives?

Short and punchy might seem like it goes against the whole idea of offering valuable and informative content, but it’s actually in keeping with that principle. What might be a more telling reason is the rise of mobile search. As of 2013, 46 percent of consumers were using mobile exclusively to research and purchase products and services, according a Telemetrics study.

Phones and tablets have smaller screens that limit how many characters users can see in email subject lines, but the 6- to 10-word sweet spot might have more to do with time. Mobile users are on the go and need to be sold on promotional messages quickly. All content should take this principle to heart – the faster valuable information can be communicated, the more likely people are to respond and become customers. So while this advice is particularly useful for businesses using email as part of their content marketing campaigns, the rest of their offerings should be similarly optimized.   

Alex Butzbach is a Marketing Writer at Brafton. He studied Communications at Boston College, and after a brief stint teaching English in Japan, he entered the world of content marketing. When he isn't writing and researching, he can be found on a bike somewhere in Metro Boston.