The power of a simple subject line

5 minute read

What do the subject lines ‘Hey’, ‘Are you in?’ and ‘Meet me for dinner’ have in common? Would you believe it, they’re all examples of subject lines used during Barack Obama’s presidential campaigning at the end of last year. The most incredible thing is that they worked; they generated interest, strong open rates and most importantly, much needed monetary support.

But how? My first reaction would be that an email with the subject line ‘Hey’ would most likely be quickly marked as spam, a sentiment shared in this Smashing Magazine article. However the results suggested otherwise; $690 million was raised for the presidential campaign from email marketing alone.

You might be thinking, ‘Well that’s an American president, a household name with a large team behind him, of course he’s going to succeed with emails like that’. Maybe, but let’s bring things closer to home for a moment. At the beginning of this month we sent the below email to a number of our customers who had recently been in touch with us.


I knew the email had been prepared and scheduled, yet when I saw ‘Can you spare two minutes?’ even I thought ‘Oh, an email from Carol’ and immediately opened and read the email. I wasn’t alone; this simple email (created using the free ‘Basic Business’ template in Campaign Designersaw double the open rate and over three times the click through rate we see in our usual monthly newsletter – the email our subscribers have arguably become accustomed to seeing.

The simplicity appears to work and I can’t help but wonder if it’s because the subject line is unusual? We’re all so accustomed to receiving emails with subject lines we’ve come to expect, that when something different comes along it catches our attention. Based on the logic that it’s the novelty factor that appeals, we could come to conclude that using simplistic subject lines isn’t sustainable. Continuous testing of subject lines is a good way of understanding if this is the case.

Going back to Obama’s campaign, an article on Businessweek’s website made reference to the extensive A/B testing his team did, looking at the subject lines, content and formatting of each email. With that in mind, here are my top tips for using split testing to find the perfect subject line.

1. The result you get might not be what you’re expecting. It’s obvious to expect the subject line to increase open rates, but it can just as easily influence click through rates. Check all the data at your disposal to help identify any concrete trends.

2. Make sure the subject line supports the content of your email. If this isn’t the case you’ll get a lot of disappointed subscribers who hit the unsubscribe or spam button. ‘Can you spare two minutes?’ supported our customer survey email message, but it wouldn’t have worked for our monthly newsletter.

3. Test one thing at a time. It’s easy to get muddled, especially if there isn’t a common denominator. Keep it simple and plan ahead; you can’t expect to find a winner if you’re testing multiple elements. I’d suggest starting with subject lines and then looking at the content within your email – but never at the same time.

4. Use what you’ve learnt, don’t be afraid of making changes. It’s all well and good testing a different subject line, but there’s no point if you’re not going to use what you’ve learnt. If you find an amazing trend by using a different subject line, make that a permanent change. You can always change it later if your results start to dwindle.

If you need any help with split testing or ideas for subject lines, drop our Support team an email and they’ll be happy to help you.

Let us know how you get on – we’d love to hear your subject line stories!