You can have the single most compelling email content ever created, and it’ll do you no good if your subject line is weak.

Often overlooked and treated as an afterthought, your campaign’s subject line is actually critical to your success. If your cold campaigns are making it to inboxes, you’ve successfully knocked on the door. If you want them to open it, your subject line has to convince them that it’s worth their time to do so.

And it has to do it quickly, while competing with piles of other subject lines. Does that sound intimidating? Don’t worry – we’ve got everything you need to rock your subject lines right here.

Keep It Short and Sweet

When you open your inbox, do you carefully read through every subject line? Or do you scan for important-looking emails first?

Probably the latter – that’s how most people check their email, particularly busy professionals who receive heaps of messages daily. You’ve got maybe a couple seconds to grab your contacts’ attention as they scan their inbox, so don’t ramble.

Think of your subject line as “the reason they should open my email”. You’ve got to deliver that whole message more-or-less immediately when the contact skims your subject. A good rule of thumb is to limit yourself to 50 characters or less.

But it’s important to note that different devices will behave differently. Some will wrap the text so it always shows the full subject line, but many will cut it off after whatever length the device can comfortably display. For example, iPhones cut the subject line off at 35 characters.

Deliver Value Up Front

Remember, with cold contacts, you don’t have the advantage of recognition. They don’t expect to see your name in their inbox, so they’re not predisposed to open your message. Quite the opposite – seeing a cold email can raise an eyebrow or two.

At this point, it’s your subject line that makes the difference between “hey, this seems worth reading” and an open, or “eh, this is spam” and a one-way trip to the trash bin. That means your subject line already needs to present value, or at least the promise of it.

It should be crystal-clear to the reader exactly what they’ll get when they open your email. It’s like an elevator pitch: sell me on opening your email in 35 characters or less. Don’t use vague language or try to be mysterious. Instead, make sure your subject line unmistakably communicates something important to the reader.

The easy way to do this is to play off whatever the primary benefit of your product or offer is. Let’s say you sell ergonomic office furniture. “Comfortable Ergonomic Office Chairs – Get Yours!” is a boring subject line. “Save Your Employees from Backache”, on the other hand, drives the point right home: your employees might be suffering from back pain because of their chairs and we’ve got a solution.

And then you follow that up in your email content by talking about the benefits of ergonomic, comfortable furniture in the office, and how it improves productivity, and so on.

Avoid Clickbait at All Costs

It’s sometimes seriously tempting to write subject lines you know can get people to click, but have very little to do with your content. Don’t do it. You might get a bump in your open rate, but you’ll also get a bump in your unsubscribe and spam report rates, because nobody likes being fooled.

If you click on an email thinking it’s going to be one thing, but it’s another, you’d feel like you’d been tricked (because it’s true). Tricking people into opening your emails is just going to make them extra annoyed when they go to delete it, because you’ll have wasted their time. Honest subject lines are key.

Personalize Your Subjects

One very powerful trick is to use personalization tokens in your subject lines. You’ve seen plenty of it in your inbox, subject lines addressing you by name are a tried-and-true marketing tactic. In the B2B world, you can take it a step further.

We’re trying to motivate the reader to open your message, and the best motivator for a professional is to solve a hurdle at work (and earn points with their boss while they’re at it). That means their first name might not be the most powerful token you’ve got.

If you have their company name instead, try using that. A Sales Manager seeing “Improve Your Sales Efficiency” might not connect that with their own advancement, but “Improve Acme Inc’s Sales Efficiency” puts the idea front-and-center that they could have a major impact on the company as a whole. That sort of angle can work wonders for B2B contacts.

Never, Ever Stop Testing

The worst thing you can do to your subject lines is fire-and-forget them, then try something random next campaign. Everything should be done with a goal in mind, and subject lines are no different.

Not only are you trying to land on a subject line that drives a nice open rate bump – you want to know why that one worked better. When you craft your subject lines, make a note of the open rate that they achieved. If it’s an improvement, try and figure out why that subject did better, and iterate on it.

That goes for every aspect of your campaigns – content and landing page as well as subject lines!