Subject lines featuring words like ‘shocking’ and ‘secret’ least effective in email marketing campaigns.
One may think adding ‘clickbait’ subject lines into marketing emails could prompt readers to read them, but a study has suggested otherwise.
The most often used clickbait subject lines like "You won’t believe this shocking secret…" were found to be the least effective in prompting readers to read them.
Emails containing "Secret of" in subject lines has a 8.69% drop in read rates compared to messages containing similar content sent under different subject lines.
Similarly, subject lines with the word "shocking" reported a 1.22% drop in read rates, the Return Path study found.
The use of benefit-based subject lines accompanied by superlatives like "fastest" were found to draw better results in gaining the attention of readers.
Benefit based superlatives like "fastest" have a 5.3% higher chance for prompting readers to read the message than similar messages sent under different subject lines.
Email subject lines with urgency based words like "limited time," "last chance," and "expiring" also have a higher chance of being read.
However, two value-based subject lines were not found to get the desired result, with these subject lines including those promoting prices and discounts.
Emails having subject lines like "discount," "save," "sales" and "clearance" as well as subjects lines with pricing references including "free," dollar signs, and percentages had low read rates.
Return Path president George Bilbrey said, "By analysing extremely large data sets collected across the entire email ecosystem, based on how real subscribers engage with messages sent from thousands of trusted brands, marketers can quickly, efficiently, and confidently test subject lines to ensure that their messages are read by as many people as possible.
"As this study demonstrates, the results are often surprising, frequently questioning or even invalidating long-held best practices."
For this study, the email intelligence company analysed over nine million subject lines received by more than 2 million subscribers from January 1st through February 28th, 2015 using its Subject Line Optimizer solution.
Subject lines having between 91 and 100 characters are among the best-performing emails with read rates of 15.1% while subject lines having more than 100 characters had lowest read rates 8.8%.