Every few months I find myself returning to the, er, subject of email subject lines, so I thought it might be worth bringing together some of the best tips from the last couple of years. The thing to remember about the subject line of a sales or marketing email is that, quite simply, it’s the most important part of the whole exercise. So many people spend hours on an email’s layout, analytics and even (if they’re smart) calls to action, but then enter the first subject line which comes into their head, almost as an afterthought. Yet an email requires the recipients to take an action (to read the thing), and the subject line is your big chance to persuade them to do so. Don’t waste it.
If you’re familiar enough to the recipients, they might open the email regardless of the subject line, as I do when I receive one from, say, my mother. With most recipients, your message won’t get quite that level of leeway. The subject line needs to intrigue, with a clear benefit to the recipient on offer. That said, for regular newsletters (with which the reader is familiar), some researchers claim that the simple “Company: Newsletter” approach can work better than unique subject lines. I think there’s a good compromise, which I use on this very email, putting an identifying tag at the front but then giving an idea of the content inside that issue.
One good tip, especially in emails which aim to get a response from readers (such as a sales enquiry) is to give subject lines a time-sensitive feel. Relating emails to the time of year, hinting that the contents are only relevant if the recipient opens it now, can be effective.
As for potential “spam hazards”, you just need to test and see. Far more of your emails than you’d care to think never arrive, often not even getting to the recipient’s personal spam bin. There are filtering services everywhere, and they err on the cautious. If you want to use words like “Free” in the subject line, I’d suggest splitting your mailing in two, using that word for just one group, and monitoring the response. That’ll give you some idea of whether it matters, for future reference.
Remember that the response from an email is the result you should be looking at, not the “open rate”. The emails which work best are those where the content delivers the promise of the subject most closely.
Finally, is there a recommended length for a subject line? It would seem not, according to research. However, the key is to get the first 40 characters right, apparently. This may well be down to the viewer’s attention dropping off, or perhaps because their view typically gets cutoff around that mark. I know I set my own email window size to be wide enough to get the gist of the subject lines in my inbox, but not so wide that it can accommodate every message’s subject.