How to leverage vague and specific subject lines to increase your email open rates

It’s a fine line. Go one direction and risk losing the trust of your audience. Go another and they might not open your email, making the assumption they already know what’s in it. Get it right and you could hit engagement gold.

Being vague or specific in your email marketing subject lines, depending on what you’re looking to accomplish, can have an impact on your open rates. Give me three minutes and I’ll explain.

Experimenting with your subject lines

Sometimes you have something very specific and timely you want to tell your audience, like “25% off sale ends today” or “Registration is now open.” The best way to drive up your open rate in these cases is often for your subject line to state exactly what the big news is. If it’s urgent, leverage that.

At other times, your audience might already know you have a big sale going on, or that registration is open, because you’ve told them about it. Or, you might have something completely different to talk to them about and, in some cases, it might be less exciting or urgent than other things you’ve sent. But, you still need people to open your emails, absorb information and take action.

In these situations, it’s worth experimenting with a vague subject line, like “Don’t forget to do this today.” In their head, they ask, “Do what today? Have I forgotten something?” And “click,” they’re in your email, remembering they wanted to buy something before it sells out or your sale ends.

Send an email that says “25% off…” again in these situations and people might not open it. Make it a bit vague, and suddenly they’re in.

Then, it’s your job to sell the reader from there, with content inside the email that gets to the point and delivers value, making it worth the click.

Try the subject line tactic with the 'From' line tactic

You can also combine email marketing tactics.

For example, if you want to send an email of appreciation to your best customers, with a special offer inside, you can use the 'From' line tactic and send it from your CEO instead of your company email address.

Then, you can use a vague subject line, like "Thank you," to drive up clicks.

Think about how a personal email like this, with a vague subject line about you, might stand out in an inbox cluttered with "Hey look at us!!" emails from corporate email addresses.

Don’t overuse these email marketing tactics

You need to be careful with your subject line tactics. Use the vague approach too often and you’ll become the boy who cried wolf. People might start to ignore you. This can especially happen if you pull people into your emails with vague subject lines and let them down once they’re inside.

It’s extremely important that the body of the email provide them with something that makes them glad they opened the email. That’s one of the things that will get them to open your future emails as well.

The specific subject line tactic can be overused as well, especially if you send multiple emails on the same topic, without changing up the content much each time. If someone didn’t buy from you in the first three similar emails about your sale, there’s a good chance they won’t buy from you in the fourth and fifth, unless you change something up.

Getting people to buy might mean highlighting a different product, creating a sense of urgency around the expiration date, using testimonials to let customers tell the story, or any number of tactics.

Your emails are going to get boring and ignored after a while, if you send readers a “25% off…” subject line several times and leave them looking at a similar email each time they open it.

Test to see what your audience responds to

Each audience is different. Though many marketing tactics can be used across multiple industries, you should study the stats to see which subject lines affect your open rates, click throughs and conversions the most.

Don't get too caught up in one stat. For example, your open rates might be rising, but how are you clicks and conversions looking? Try making small tweaks to see which tactics move which needles and by how much.

Tie your email marketing approach into a larger strategy

A tactic can’t just be a free-standing gimmick—it has to be part of something larger. Once your subject lines draw people in, the content of your marketing emails has to deliver in order to get them to take action.

And then, if you're selling something, you need to send readers someplace where a transaction can occur easily. All the subject line tactics in world won't be enough, if you don't make it easy for people to buy what you're selling.