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Are You Testing Email Subject Lines?

Are You Testing Email Subject Lines?
For both direct mail and email, we often talk about split testing messaging, images, and offers. Recently, a study of email subject lines showed just what a difference knowledge of small variances can make.
In its “Subject Line Analysis Report” (2013), Adesta analyzed the subject lines of over 2 billion global emails. It found that even subtleties in wording can increase or decreases open rates, conversion rates, and other metrics substantially, even words that are counter-intuitive to what you might think.
You would think that everyone wants free stuff, right? But Adesta found that when used in the subject line, the word “free” actually depressed the open rate vs. the average by 3.0%, while “free delivery” increased it by 50.7%. Likewise, the word “alert” increased the open rate by 38.1% vs. the average, while “learn” decreased it by 35.5%.
But marketers have to be careful. Higher open rates don’t necessarily translate into more orders or higher customer engagement. In Adesta’s analysis, for example, “free delivery,” had a higher open rate, but it’s unsubscribe rate was 82.4% higher than average! This suggests that while marketers may be using a highly effective subject line, the messaging and offer are not matching up.
Whether you are marketing in print or email, or perhaps using email as a follow-up or complement to print, the larger message is to test everything, especially headlines and subject lines. And remember that testing is time-sensitive. Customer attitudes and preferences can change, so you need to keep testing over time to keep track of constantly changing market conditions on the ground.

Optional link to the report: