Subject Line Do’s and Don’ts

It’s one of the most talked about elements of email marketing and a good email subject line can make a campaign – much like a bad subject line can ruin one. In part 2 we’ll discuss writing a subject line that captures your audience, but for now we’re going to look at the ‘do not’s of subject line creation.

Here are the golden rules, and each start with the words ‘Avoid’ or ‘Do Not Use’.

• Do not use the words free, discount, offer, savings (especially with the word huge before it) or promotion. These are as bad as any of the words you thought to avoid like ‘Sex’ and ‘Pills’ for example. In fact ISPs and spam filters have a list of words they believe to be dubious.
• Do not use any form of punctuation. Exclamation marks are by far the biggest offender here but grammar is of no concern to a spam filter so leave the commas, hyphens and colons out of it.
• Avoid putting capitals at the beginning of words to grab attention. Capital letters throughout a subject line are a great way to find yourself stuck in a junk folder. It’s nothing personal, it’s just spammers love to capitalise everything to grab attention.
• Do not use currency symbols or percentage symbols. ‘£’, ‘$’, ‘€’ and ‘%’ symbols are the easiest way to get picked up by spam filters so avoid them. And the filters aren’t stupid so ‘pounds’ won’t be the answer to your symbol free subject line.

At the time of writing this, we have a few other things to avoid like the plague. ‘Apple’ and ‘iPad’ are good examples of how to get straight into the junk folder, but anything tablet related or any brand that spammers use to grab attention in terms of free products to give away are causing all kinds of issues to marketers.

Of course spam scores are accumulative, and it might be that one little niggle in the subject line might not be too problematic, but it’s one of the main causes of email getting treated as spam and if you’re content is full of ‘hit words’, images and prices, it may just be that a niggly subject line is enough to get your campaign junked before its had a chance to reach the recipient, so best practice is advised almost every time…

…What? There’s an exception? Well here comes a bit of truth about direct marketing in general. People like free stuff. In fact they like it so much that it makes them look at things just to see what’s being offered for free. The same is true for emails. If you took the spam filters, email browsers and ISPs out of the equation, an email subject with the word free in it, or ‘FREE’ is always opened more than one that doesn’t – easily raising opens rates by 50%. That’s why spammers use it so much. The theory is that although there will be more chance of the email getting treated as spam and rejected or junked, the sheer volume of people that will open it far outweighs the volume of those with spam filters.

Think about it. You send an email with a subject line describing your product or service to 10,000 people. You normally get an open rate of 25%, so 2,500 people see it. If one in 5 people have a strict-ish spam filter and you send your email with ‘FREE’ in the subject to 10,000 people, then you eliminate 2,000 people straight away. You now have only 8,000 people who received your email. But it’s more appealing because it’s offering something for FREE! And has improved your opens by half as much. Your 25% has increased to 37.5% and now your campaign has been read by 1,000 more people. If your CTOR (click to open rate) rate is 10%, then 100 more recipients have interacted with your campaign and are on your call-back list, or even better have bought your product online directly from the promotion.

Subject lines are tricky things, and the best way to find out was works for you is by testing and analysing. Of course there is help here. Split-testing, accurate reporting over a period and understanding your customer or subscriber base are a good place to start, but any experienced email marketer (not email marketing provider – you need a professional that understands the medium and the principles of direct marketing and consumer data analysis) should be able to help you get the most out of your campaigns.