Open this, [NAME]! Why personalized email subject lines work

Ed Finkel | Oct 12, 2018

Sections Marketing

Want more clicks on a marketing email? Put the recipient’s name in the subject line. That’s according to experiments by Stanford’s Navdeep S. Sahni and S. Christian Wheeler, along with Chicago Booth’s Pradeep K. Chintagunta.                                                         

The researchers worked with three entities: a major online test-preparation company; MercadoLibre, the largest online marketplace in South America; and Stanford University. In each case, they sent some emails that contained the recipient’s name in the subject line and other emails that did not. 

The study explored three potential ways that personalization could affect the success of email marketing. Could naming an addressee in the subject line orient attention toward an email? Could it serve as a positive cue, as most people have favorable attitudes about themselves? Or could it somehow help communicate that the email content is relevant?

The researchers hypothesized that perception of relevance depended at least in part on the actual content of the message. So while they kept the email content the same for MercadoLibre and Stanford, they varied the content in the online test-prep company's emails by offering a discount to some recipients but not others.

When emails went to the test-prep customers, adding a recipient’s name to the subject line increased the probability of the addressee opening the email by 20 percent, from about 9 percent to about 11 percent of emails. This translated into a gain in sales leads, valued at about $100 apiece, of about 30 percent. It also resulted in a 17 percent decrease in the number of people unsubscribing. 

In one of the campaigns run with the company, adding a name to the subject line generated 35 extra sales leads and saw 85 fewer people unsubscribe, boosting the audience for future marketing campaigns. As a result of the increase in sales leads and a reduction in the numbers who unsubscribe, relative to the baseline, the online test-prep company now adds the recipient’s name to email subject lines, the researchers say. 

Adding a name to the subject line also increased recipients’ engagement at MercadoLibre and Stanford. And at the test-prep company, offering a discount increased the number of leads only when an email was personalized.

The findings suggest that personalizing emails benefits marketers significantly, even when the content is not particularly informative—because the personalization leads to greater consumer “processing” of the advertising messages. 

“Our investigation of the mechanism shows that personalized content can be noninformative but still be valuable in garnering a consumer’s interest and increasing the likelihood of her processing and responding to the rest of the advertising message,” the researchers write.