Specifically, results showed that the most effective email sign-off is “thanks in advance”.
For the study, Boomerang looked at closings in over 350,000 email threads from mailing list archives in which, they wrote in a blog post, many emails involved “people asking for help or advice, hoping for a reply”.
Then they picked out the eight email sign-offs that appeared over 1000 times each and figured out the response rate linked to each sign-off. Here’s what they found:
- “Thanks in advance” had a response rate of 65.7 per cent
- “Thanks” had a response rate of 63 per cent
- “Thank you” had a response rate of 57.9 per cent
- “Cheers” had a response rate of 54.4 per cent
- “Kind regards” had a response rate of 53.9 per cent
- “Regards” had a response rate of 53.5 per cent
- “Best regards” had a response rate of 52.9 per cent
- “Best” had a response rate of 51.2 per cent
The average response rate for all the emails in their sample was 47.5 per cent.
The Boomerang blog post also cites 2010 research from Adam Grant and Francesca Gino, which found that participants who received an email from a student asking for feedback on a cover letter were twice as likely to help when the email included the phrase, “Thanks so much! I am really grateful.”
Interestingly, three separate etiquette experts previously told Business Insider that “best” is the most appropriate way to end an email. And one such expert said that “thanks” is “obnoxious if it’s a command disguised as premature gratitude”.
The Boomerang analysis didn’t measure how recipients felt about the sender – just whether they responded. It also didn’t measure the power dynamics at play. Maybe your boss signs their emails “best” and they always get an answer.
Bottom line: If you want a response to your email, it can’t hurt to end it with an expression of gratitude. Thanks for reading!