How to write a compelling subject line: dos and don’ts

Email marketing expert Kath Pay shares her dos and don’ts on how to craft a compelling email subject line…

 How to write a compelling subject line: dos and don’ts

DO write your subject line first

The simple act of creating your subject line first will help you to stay focused on the objective of the email and achieve better results.

Over the years I’ve trained hundreds of email marketers and 90% of them have admitted that they save writing the subject line until a few minutes before they push ‘send’, which often results in a hurried and potentially ineffective subject line.

By writing the subject before you do anything else you are not only allowing yourself the time to craft a persuasive and effective subject line, but you’re also using the subject line to prepare the framework of a persuasive email, designed to get the reader to take the next action.

DO focus on what success looks like

All too often we think the objective of an email is to gain as many opens as possible, but that’s not often the case. It could be event registration, downloads, product purchases… Don’t be surprised if you find that emails with the highest-opening subject lines don’t always equate to the emails with the highest conversions.

So by keeping focus on the real objective of the email you’ll find it easier to write subject lines that attract the audience most likely to convert, rather than a bigger audience who are less interested in converting.

DON’T over-promise

You’ve probably read emails that have a catchy subject line to lure you into opening, yet leave you feeling disappointed when the content doesn’t quite live up to its title.

A subject line should work together with other elements of the email to convey your overarching message. Subject lines offer a promise and set expectations, which the content of the email and any landing pages need to deliver on.

Disconnects can confuse readers. So even though a clickbait-style subject line might have spiked your users’ interest, gaining lots of opens, if the content itself doesn’t flow from the subject line this higher open rate won’t necessarily result in conversions.

Once you’ve disappointed your reader and lost their trust, you’ll have to work twice as hard to regain it later.

DO keep learning

I recommend thinking about every email as a customer survey of your target market.

Aim to learn something from every email you send – not just which subject line gains the best results through an A/B test, but how elements like tone of voice and messaging affect your opens and conversions, too.

For example, you could test the effectiveness of an ‘exclusive offer’ subject line vs a plain ‘30% off’. New prospects, unfamiliar with your services, might respond better to the 30% off proposition – but existing customers could feel more valued, and therefore engage better with, the idea of exclusivity.

There are lots of online testing tools available to help. Touchstone is a nifty tool that virtually tests a subject line’s open, click and delivery rates (using historical data). It’s well worth a look.

You might also find that different audience segments respond differently to the same subject line; testing is a quick and easy way of gauging how your varied audiences behave, giving you valuable insights to use across your wider digital marketing. 

About Kath Pay

Kath Pay is one of the World's Top 50 Email Marketing Influencers (Vocus, 2014). She heads up training for Econsultancy on Personalisation and Email Marketing, and runs her own agency, Holistic Email Marketing