10 LinkedIn InMail Subject Line Tips for Higher Response Rates

If you are looking to start a conversation with a prospect, influencer, or industry leader outside your current network, you might consider utilizing LinkedIn InMail. Guaranteed delivery, above-average open rates, and the ability to target high-value leads are just some of the benefits that InMail offers. 

However, before you get too excited, it’s important to remember that these benefits are useless if your subject line doesn’t compel your prospect to open the message.

What’s more, LinkedIn InMail is also limited and somewhat costly, making a bad subject line even worse.

Only premium (paid) LinkedIn accounts have access to the InMail feature, and their lowest tier (“Premium Career”) allows only five messages per month. This high-barrier to entry contributes to the benefits of InMail, but it also increases the need to craft a compelling subject line. 

And what does success look like for InMail? 

That depends on your objectives, but if you can get a response back within 90 days, LinkedIn will give you another InMail credit. That being the case, you’ll want to make responding to your message your go-to call to action for InMail. More responses mean continuing conversations with current prospects while gaining the ability to reach more people without paying extra.

With so much at stake, here are ten tips to consider as you craft your InMail subject lines. 

Make it clear that the message content is valuable

If you want your prospect to open your message, put yourself in their shoes. Based on the subject line, would they want to open your message? If you want your message to be read,  you need to clearly communicate the value of your message in your subject line.

Here are some questions to consider as you write your subject line: 

  • Who is my reader, and why would they want to read my message?
  • Does my subject line promise a benefit or reward for reading the message? 
  • Does my subject line relate to the message that follows? 
  • Is my subject line clear about what my reader can expect to find in the message? 

Address pain points

Your ability to resonate with your recipient’s struggles and pain points is a great way to create a new connection.

For example, if you noticed that your prospect recently moved to your town and you’re hoping to grab a lunch meeting, you use the subject line, “Have you found your favorite lunch spot yet?”

This subject sympathizes with the pain of learning a new city while implying that your message contains helpful information. 

In your message you might go on to introduce yourself, share several of your local favorites lunch spots, and express your desire to meet for a future lunch.

Personalize your subject lines and make them relevant to your reader

Adding a personal touch to your subject line is a good way to encourage the reader to open your message. 

When it comes to personalizing subject lines, we often think of simply adding the recipient’s name. This can be beneficial on occasion, but after extensive testing, the folks at Litmus shared that, in most cases, “…adding the recipient’s first or last name does not significantly improve open rates.” 

For cold emails, adding a first name can also make your message feel like spam, increasing the chances of your recipient ignoring your message and having negative feelings associated with you. 

Better ways of personalizing your subject line include: 

  • Congratulations on posted work and life events. (“Congratulations on your new promotion!”)
  • Leveraging localization. Mentioning the recipient’s city to show that the message is relevant.  (“Question for you about Lufkin, TX…”)
  • Referring to their job title. (“The best gear for audio engineers”)

Mention common ground

When networking and building new relationships, it works well to  find common ground when initiating a conversation. Finding these connection points and adding them to your subject line increases the chances of the person opening your message. 

For example, a mutual acquaintance is a great way to start a conversation. Something like, “John Farmer thought it might be good for us to connect.” 

Another example of mutual overlap is mentioning a shared interest in your subject line. For example, “Have you tried hiking Glacier National Park yet?” 

Make it crystal clear

Your subject line might be great, but if your subject doesn’t directly align with your message’s content, you won’t get a response. No one likes a bait and switch.

Make sure that your subject line is clear about what the recipient can expect when they open your message. 

Keep it short and sweet

LinkedIn InMail limits your subject line to 200 characters, but you should probably limit yourself even more. Keep your subject line as short as you can without sacrificing clarity. To give you a frame of reference, Litmus shared these helpful statistics regarding email subject lines. 

  • Emails with 28–39 characters in the subject line had the highest click rates.
  • 4–15 characters: 15.2% open; 3.1% click
  • 16–27 characters: 11.6% open; 3.8% click
  • 28–39 characters: 12.2% open; 4% click
  • 40–50 characters: 11.9% open; 2.8% click
  • 51+ characters: 10.4% open; 1.8% click

InMail is a more exclusive, less competitive online mailbox, so there is a chance that you have a bit more wiggle room than with classic email, but is it worth the gamble? 

Most of us check our messages on the go, which is a good reason to quickly get to the point. If your recipient can’t get a clear idea of what your message holds because they can’t read the full subject line, it dramatically decreases the odds of them opening and responding. 

Use the statistics above as a frame of reference as you craft your subject line. 

Know your audience and adjust tone accordingly

It’s important to consider the tone of your subject line before sending your message. Tone is tricky online because it doesn’t translate the same way to everyone. For example, you might craft a subject meant to communicate a sense of fun and energy, but it lands on your recipient as unprofessional. At other times, you may try to write with a professional tone, and have it land as cold and overly formal to your recipient.

The best way to avoid tonal miscommunication is to know your audience. How does the person you’re writing to tend to talk online? How do people similar to them talk online? Try to match their tone and language as best you can. 

Add a sense of urgency

If you want your prospect to open and respond to your message, consider adding a sense of urgency. The goal is to make it important for your recipient to respond promptly. 

Even when we intend to respond, without a deadline or a sense that things are time-sensitive, we can put off responding until it becomes forgotten or embarrassingly late. 

If you can, encourage your recipient to open and respond in a timely manner. 

There are ways to do this without being pushy. For example, instead of the subject line, “Meet for coffee?” you might choose to say, “Meet for coffee this Saturday?” Instead of saying, “Free webinar for new entrepreneurs!” you might say, “February 12th – free webinar for new entrepreneurs!”

You want opening and responding to your message to rise to the top of your recipient’s list of things to do in the near future. 

Ask a question that is answered in your message

Questions are effective motivators because they introduce a bit of mystery. Straight information can be ignored, but stories are compelling and engaging. Crafting a good question for your subject line can entice your recipient to open your message to find the answer.

Or even better, introduce a new mystery in your message that’s resolved only by responding. The best marketers and communicators master the art of leaving a breadcrumb trail that creates an ongoing desire in their audience to learn more. These storytelling tactics are often called “cliffhangers” or “story gaps.” 

For example, the subject line “Is your newborn causing you to lose sleep?” introduces a question while suggesting a solution is contained in your message. In your message, you might mention your best idea for getting rest in the newborn season. 

You could end your message with, “I’ve got five more ideas for you to try during the newborn season. Didn’t want to overwhelm you with too much in this message, but I’m happy to share the rest! Shoot me a message, and I’ll get back to you with the other ideas.” 

Experiment and measure results

One of the great things about LinkedIn InMail is that it lets you run multiple campaigns at the same time. This gives you the ability to test and experiment with various subject lines.

Effective subject lines are more of an art than a science. Testing different subject lines can help clarify which subject lines resonate with your audience and lead to the highest response rate.

When testing and experimenting, it’s best to make small changes. Changing a word or two can help narrow down exactly what works and what doesn’t. 

Cut Through The Noise

LinkedIn InMail’s limits create an opportunity to cut through the noise while trying to reach new prospects. Pair this opportunity with some of these tips for a thoughtful subject line, and you will have increased the odds of starting new conversations that lead to more sales, influence, and a larger network.

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