Should your email subject lines be a specific length?

A must-read article for anyone who sends out promotional emails has just appeared on the Mailchimp blog. This Just In: Subject Line Length Means Absolutely Nothing discusses an analysis of billions (yes, billions) of emails, and found little or no correlation between performance and subject line length, something which it’s often argued is quite important. As the author points out, you shouldn’t blindly follow generalised “rules”, but find out what works with your own audience. I know it’s hard, with such small circulations and infrequent mailings, but it should be possible to develop some theories and test them over time.

And never stop testing. I discovered last year that for this daily article, emails with questions in the subject line received a higher open rate than ones with statements, or even offers. So I decided to use a question every day. Too much? Possibly. If my testing suggests that’s the case, you’ll be the first to see.