When you send out promotional emails, how much time do you spend on the subject line? I’m willing to bet it’s not enough. In the past, I’ve agonised for hours over the artwork for the envelope on a postal mailshot, yet it’s easy to just spend ten seconds on the online equivalent of the envelope: the subject line. Faced with dozens of emails in an inbox, an increasing number of people just skim through the subject lines, read (and file) the interesting ones, and delete the rest. And yet what determines whether an email gets opened or not comes down to just two things: your recognition with the recipient, and the attractiveness of the subject line.
There are loads of good articles online about how to craft a great email subject line, and I won’t try to summarise them here. However, most of them will tell you to test your subject lines, and to keep testing. That’s fine if you’re sending to tens of thousands of recipients; you’ll be able to trial an email to a selection of recipients first, using different subject lines, and see which gets opened (and more importantly, acted on) the most. Then you can send to the rest of your mailing list using what you’ve learned. But for most industrial and scientific businesses, the size of the circulation isn’t enough to allow statistically-valid trials. If your email is going to 250 customers, and you send one a month, you probably just have to take the best general advice and hope.
Having been responsible for a company which sent out something like ten million emails (all requested!) to engineers and scientists 5-10 years ago, I was able to see at first hand what worked. My conclusion was that the subject line became less important over time, as recipients increasingly associated our name in the “sender” line as representing emails with potentially interesting content, and probably didn’t look at the subject line, as you wouldn’t with an email from, say, a relative. However, the subject line was important to begin with, and if your emails are infrequent, that honeymoon period may last a long time. Unless everyone on your list has been reading your emails for years, I’d suggest giving your subject lines plenty of thought.