Uncovering What Makes the Perfect Sales Email Subject Line

A quick look at your analytics may not tell you much about your subject lines. In fact, a lot of email marketers simply overlook the subject lines of their best and worst performing emails, passing them off as completely random.

According to Superoffice, 47% of email recipients open an email based on the subject line and personalized email subject line can lift open rates by 20%. 3 words in the subject line convert to 20% more opens, says our VP of Customer Success Curtis Bendt. The fact is, however, that most successful sales emails will have a subject line with similar characteristics. So, with that in mind, we’ve taken a closer look at what exactly goes into a high performing sales email line that can boost your sales process.

Getting straight to the point

Most good subject lines are short and to the point. If you consider that most of the email platforms out there cut off subject lines that run over fifty characters, it’s vital that you get your message across concisely. A study carried out by Boomerang found that over the course of forty million emails, it was subject lines that stuck to just three or four words that achieved the highest levels of engagement. The length of time the average user spends scrolling through their inbox isn’t that great, so a short, well-written subject line will have a better chance of grabbing their attention.


Increasing the open rate is only the start of the battle, and a common mistake many email marketers make is by thinking that by merely increasing the open rate, they’ll be increasing their conversion rate. In order to do that, they’ll craft an intriguing subject line that doesn’t necessarily reflect the content of the email. All that ends up doing is alienating their prospects who feel they’ve been misled, so it’s always a good idea to keep the content of the email firmly in mind when crafting a subject line.


It’s always tempting to create a witty subject line, but studies have shown prospects tend to prefer subject lines that are completely clear about the content of the email. Research carried out by AWeber Communications discovered that subject lines which were straightforward and easy to understand received over 500% more clicks than subject lines which were deemed to be ‘witty’ or ‘amusing’. A common mistake with witty subject lines is that they rely on the prospect to open the email in order to ‘get’ the joke. Instead of creating a joke around an offer or deal you may be running, if you have something of value to offer your prospects, then it’s probably best to come out and say it.

Keeping it personal

You’ve probably heard that it’s always best to keep things personal with email marketing, and it’s exactly the same with subject lines. Whilst prospecting, you may find out more information about certain contacts, and you can use that to your advantage in a subject line. If, for example, you discover that one particular contact works in a corporate environment, whilst another works in an office with a more laid-back approach, you can cater to them individually by changing the tone of the subject line. It’s quick and easy to incorporate the name of a contact or a company name into a subject line, so if it’s relevant, it’s always a good idea to make it as personal as possible.


No matter what you’re selling, whether it’s a product or a service, your prospects are going to want to know if it works and what it can do for them before they even contemplate making a purchase. To show that you have a product or service that’s worth buying, an evidence-based subject line based on the findings from a case study is always a good idea, simply because this shows your prospects that what you’re offering works.

The human touch

With over one-hundred marketing emails on average being received daily, prospects are more than used to being sold to. That means any email that appears to be promotional usually isn’t prioritized. In order to stand out from the raft of marketing emails, it’s important to get the basics right, and that means adopting a human approach when it comes to the subject line. Ensuring that only the first word of the subject line is capitalized may seem like a small change but it can make a big difference in how your email is seen. It’s also a good idea to avoid using too many capital letters or exclamation marks, along with ‘sales type words’ such as ‘promotion’ ‘discount’ and ‘offer’.


Without being too ‘sales-y’, you can still set a deadline for your lead generation campaigns, and the subject line is the perfect place to do it. You have a lot of competition in your prospect’s inbox, so if there’s no deadline in place, your prospect could put off opening it for a day, a few days, a week or just not open it at all. A deadline encourages quicker opens and can be achieved by putting a timer on the offer in your subject line.

Remember the preview text

Once you’ve got the perfect subject line in place, it’s important you don’t forget about the preview text. If you’ve managed to grab your prospect’s attention with the subject line, it’s highly likely that they’ll turn their attention to the preview text before deciding whether or not to open the email. These often show up side-by-side, so it’s important not to repeat the subject line, but rather to give a snippet of the email itself. If you’ve got some stats in your email, the preview text is a great place to put it in order to entice your audience by showing them you’ve got evidence to back up the claims in your subject line.

Getting the perfect subject line time and time again for your sales email can be tricky. If you require any help with getting your message across and improving the conversion rates of your email marketing efforts, then simply speak to our team today to find out how we can help.