The 5 Words That Make People Open Emails

Did you know that the difference between "sale" and "save" can make or break an email campaign?

Written by Mira Shenker

Wondering why your email campaigns are getting no response? Allow digital marketer Adestra to take a stab at it. According to them, marketers seem to choose the least sexy, most boring words to build email subject lines. So, they tested 287 keywords in subject lines across a sample of 2.2 billion emails to see which work and which don’t. They measured the results for each keyword against average open rates, click rates, and unsubscribe rates (by industry).

Here are some of the words with higher than average open and click rates overall, but lower than average unsubscribe rates (basically, these are five magic words that yield all the desired results):






In terms of newsletter frequency, “daily” is the winner. The trigger word “monthly” got -26.6% opens and -37.0% clicks, while ‘”weekly” got +27.1% and +50.6% and “daily” got an impressive +27.8% and +100.3%.

Among the other key findings:

People love free stuff. You probably knew that. But did you know that the word “sale” resulted in a +60.7% click-through rate, while “save” yielded -25.2%? That alone is a valuable lesson in the importance of choosing your words carefully. Including “free delivery” or “% off” also proved effective, but Adestra warns against using them too often. If you do nothing but hard sell and offer discounts all the time, your customers will get bored and tune out.

Make sure your content is good. Content marketing only works if your content is authoritative and useful. Because people have been burned before, they seem to have negative responses to works like “report” or “webinar.” But they’re still receptive to “news,” “bulletin,” and “video.” No matter what you do here, remember that if your content is weak, you’ll be labelled a spammer.

Read Quality Content Is Essential to Winning the Marketing War

Personalization can work if you have clean data. First of all, if you’re going to personalize a subject line, the email body and destination page on your website should also be personalized. More importantly, make sure you’re using up-to-date data so you don’t send someone an emailed personalized for the wrong person.

Read How Digital Culture Has Changed Marketing

Adestra’s Parry Malm cautions that these relationships are correlated, but not necessarily causal. There are too many variables in an email campaign to pinpoint exact causation. The report showed that certain words seem to have more appeal than others, but it also found that there is lots of short-run variance in every keyword sample. Malm’s advice: never stop experimenting. What works one week may not work the next, so keep testing out words to find the ones that consistently deliver.

Need more advice on crafting expert emails? Read The 7 Elements of a Perfect Email

Originally appeared on