In the world of email marketing, subject lines are king. These 40 to 50 characters (or less!) command a lot of respect. They’re only a small cog in the email marketing machine, but a lot hinges on them.

A bad subject line can have a ripple effect on the rest of your email campaign, as it doesn’t really matter what’s inside your email if no one opens it. Given the importance that subject lines play, we recently shared our top eight tips for crafting an effective subject line.

But what does this advice look like when you put it into action? Here are nine subject line ideas that embody these principles:

  1. An Ironic Statement/Question: You wouldn’t make these email marketing mistakes, would you?
  2. The Have to Know: 4 out of 5 marketers make this mistake every day, do you?
  3. An Incongruous Match: The surprising trait that marketers and giraffes have in common
  4. The Joke: What did the hippo say to the email marketer?
  5. The Personalized Approach: We love [Company Name]’s blog, but there’s one thing you’re missing
  6. The Trending Topic: What the World Series teaches us about email marketing
  7. A List: The top 5 email marketing mistakes you don’t even realize you’re making
  8. The Time Sensitive Offer: We never do this… but we are for today only
  9. The Warning: Don’t do this! 5 email marketing traps you need to avoid

Why These Subject Lines Work

What makes these subject lines so compelling? They’re all different, but they have several things in common:

  1. They create a sense of urgency: Obviously the time sensitive offer creates urgency by making clear that something is only available for a limited time, but when you think about it, it’s not the only one that does that. Most of these subject lines pinpoint mistakes the recipient could be making, and what happens when you find out you’re making a mistake? You want to remedy it — and right away.
  2. They’re simple: All of these examples are quick and to the point. Whether you’re quickly scanning your inbox on your phone or trying to catch up on emails at your desk, you can quickly and easily grasp these subject lines. Let’s leave Shakespeare out of the inbox.
  3. They spark curiosity: We can’t speak for everyone, but we sure are curious what marketers and giraffes have in common (does anyone know the answer?). If you can leave people wondering, it won’t be long before they open your email, if for no other reason than to satiate their curiosity (it then falls on what’s inside to keep them hooked).
  4. They inject the recipient into the message: Most of these subject lines directly acknowledge the recipient with the word “you” (or “us”). This approach makes it conversational and gives recipients the sense that they’re part of something. Additionally, it makes it feel as if you’re speaking directly to them, not at them.

The Subject Line Litmus Test

There’s no formula for creating a perfect email subject line, but a general litmus test to determine if you have a good one is: Do you want to know more?

While you certainly need a subject line that grabs attention, the true measure of whether or not it will get someone to open your email is if it leaves them wanting more. If your subject line doesn’t provide a reason to keep reading or gives everything away up front, then it’s time to go back to the drawing board.