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. 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.
Emails that closed with a variation of thank you got significantly more responses than emails ending with other popular closings. Email closing "thanks in advance" had a response rate of 65.7%, while "best" and "best regards" had a little over 50%.
The difference a simple “thanks” makes in getting a reply was even clearer when we compared emails with “thankful closings” 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.