When you’re drafting an email, ending it is the easiest part. Whether you sign-off with “Warmest Regards,” “Thanks,” or “Keep On Keepin’ On,” it only takes a second, and you probably don’t give it a second thought. Do email closings even matter? And if so, is “best” really best? We looked at closings in over 350,000 email threads, and found that certain email closings deliver higher response rates.
For our study, we used messages from mailing list archives of over twenty different online communities.1 These emails proved to be a great sample for looking at variations in response rate, as many entailed people asking for help or advice, hoping for a reply.
Email closings are largely determined by the setting of an email. You might sign a message to your mom with “Love,” but would (hopefully) choose a more formal closing when writing to your HR person. So first, we wanted to get an idea of which closings were used in these online communities.
Eight email sign-offs (pictured, in order of popularity) appeared over a thousand times each.
Not much of a surprise here: these eight closings are all common email sign-offs in general. As none of these endings seem specific to online communities, any trends we find should be relevant for anyone who emails. So now for the moment of truth: how did these closings correlate with response rate?
Emails that closed with a variation of thank you got significantly more responses than emails ending with other popular closings.
|Email Closing||Response Rate|
|thanks in advance||65.7%|
(all emails in sample)
The difference a simple “thanks” makes in getting a reply was even clearer when we compared emails with “thankful closings”2 to all others. Emails where we detected a thankful closing saw a response rate of 62%. This compared to a response rate of 46% for emails without a thankful closing. Closing with an expression of gratitude thus correlated with a whopping 36% relative increase in average response rate compared to signing off another way.
After doing some sleuthing, we realized our findings actually reaffirm a 2010 study published in the Journal of Personality and Social Psychology titled “A Little Thanks Goes a Long Way.” In this Grant & Gino study, 69 college student participants got one of two emails asking for help with a cover letter. Half received an email that with a line that included “Thank you so much!” The other half got a similar email, sans an expression of gratitude. The study found that recipients were more than twice as likely to offer assistance when they received the email that included “thank you.”
Also noteworthy was that generic email sign-offs like “regards” had lower response rates. And it turned out that “best” was in fact worst among popular email closings. Ending an email with “best” had the lowest average response rate when compared to other email sign-offs that appeared 1,000+ times.
Among closings seen at least 1,000 times in our study, “thanks in advance” ended up correlating with the highest response rate, which makes sense, as the email’s recipient is being thanked specifically for a response which has yet to be written. There’s a bit of posturing involved with this closing, but it turns out it works pretty well. But no matter how you express your thanks, doing so certainly appears to be your best bet in closing an email if you want a response. Interestingly, all of the email sign-offs that appeared 1,000+ times saw higher email response rates than the overall average response rate across all emails in our sample (which was 47.5%).
This isn’t the first time we’ve looked at attributes of email and their relation to response rate. We previously found that email length, tone, grade level, and even subject line length also matter. If you want to write emails that get responses, you can also check out Respondable, a free feature built into Boomerang for Gmail and Boomerang for Outlook. Respondable analyzes your email in real-time and lets you know about changes that might help you get a reply! It’s one of many Boomerang features that help people email more productively.
If you geek out about emails and data science as much as we do, we’ve documented our approach (and findings) for this blog post in a Jupyter Notebook. You can check out our study (or even extend it!) by viewing the code behind it. We’re thankful for the community behind the tool that helped us collect and analyze these emails, and are excited for the future studies we can do using this same data!
1. We used an open-source library that allowed us to thread emails from lists that ranged from support emails for Pidgin (an instant messaging client) to UCLA’s Religion Law list. Many of the larger lists revolved around open source software and operating systems (e.g., Python, CentOS). We used Regular Expressions to extract closings from these emails, and were thus able to find how different closings correlated with response rate.
2. For “thankful closings,” we checked the closing detected in each email (if any) to see if “thank” was part of it, which includes thanks, thank you, thanks in advance, and more.