Read rates vary greatly depending on subject line keywords, phrases and lengths
What do “still time” and “prettiest” have in common for retailers? According to February 2015 research by Return Path, they’re the most effective keywords used in retail marketing email subject lines, with respective average read rates of 33.73% and 32.50%. “Cheapest” ranked third, while command words “download” and “register” rounded out the top five, all with read rates hovering around 25% on average.
Return Path also looked at what not to do for retail email subject lines. “Get rid of” was the least-read, with an average rate under 5%. Despite the effectiveness of “offer,” other money-saving phrases “2-for-1” and “half off” didn’t fare as well. And while “expire” and “hurry” were relatively well-read, other urgency keywords “extended” and “running out” landed in the bottom 10.
It takes more than choosing the right words to drive readership; length matters too. The research found that retail marketing emails with between 61 and 70 characters had the highest average read rate, at 17%. Interestingly, the second-most-read emails jumped to subject lines with between 91 and 100 characters.
However, retailers weren’t leveraging the most effective lengths. Instead, messages were most likely to have between 41 and 50 characters, at 25% of the total. In comparison, just 6% used the most-read length (between 61 and 70), and only 1% used between 91 and 100 characters.
Testing email subject lines can help retailers figure out what to use, and not use, when sending a message out to the masses. According to October 2014 research by Howling Mad, call-to-action and subject line length phrases were the most popular email subject line elements that marketers worldwide commonly split-tested, cited by 77% and 58%. However, further responses indicated that marketers could be doing more to investigate other elements. About four in 10 tested different adjectives, 36% looked at the effect of including price/discount and 30% split-tested price differentials; a quarter tested the inclusion of different product features in subject lines, and just 10% punctuation. Overall, Howling Mad determined that marketers weren’t going all out when it came to subject line split-testing.
For retailers to get the maximum results from email efforts, testing subject lines to determine top phrases, keywords and lengths is critical.