Find your emails falling flat? You may be missing a key element of a strong email marketing program: segmentation.

Email list segmentation ensures that messages you send to your audience are relevant to their relationship with your brand, where they fall in the buying process, and what kind of customers they are. Whether you’re pushing promotional or informative content, you must reach your audience with emails about which they may actually care.

Your audience ignores irrelevant sales messages all day long. What makes you think they won’t ignore yours? Without email list segmentation, you greatly increase the risk of sending emails that will go unopened.

According to MailChimp, segmented email campaigns (by their customers) are nearly 15 percent more likely to get opened than the list average. In an age of hyper-relevant content, your marketing can’t afford to cast a wide net. It needs pinpoint accuracy.

The right software is a critical part of the segmentation process. If you haven’t yet, you’ll need to invest budget into a powerful email marketing platform. That way, you’ll be able to get the data you need to get your segmentation working right.

Ask three important (and related) questions when approaching email list segmentation.

Who is your audience member?

What details do you know about subscribers you haven’t yet converted to customers? This could be information you captured after the subscriber filled out a lead form or email subscription form. It might include details like age, gender, work, interests—whichever details are important to your brand that help you differentiate content or products.

Understanding qualitative details about your email subscriber helps you dig deeper into their motivations. That way, you can understand why that audience member wants to receive those emails and how you can tweak content to best reflect it.

If you’ve built out user personas for your brand, you can match subscribers to those personas more easily. With more relevant content come higher open rates, translating into more conversions and happier customers.

Where are they in the purchase funnel?

Understanding your buyer’s journey is a critical (and much more measurable) part of a successful marketing program. It also plays a major role in email list segmentation, too.

Consider the difference between a subscriber who recently signed up and one who has followed links and clicked around your website. You’d be right in assuming an introductory email with useful content may be more pertinent to the new subscriber than a sales message offering a promotion for a random product.

B2B companies tend to have a longer decision-making process. You may snag a subscriber based on the useful content you create about their industry or role. You convert that customer by presenting service-oriented content when they start visiting pages related to requesting a quote, for example.

What previous purchases or other actions have they made?

As you learn more about your subscriber, you can do more to narrow your emails based on their behavior. This is especially useful for product-oriented companies that make the bulk of their income from recurring revenue.

When you know what a customer has purchased in the past, you can make more accurate guesses as to what they may need in the future. As a result, you can serve up more relevant content.

Take this concept a step further by analyzing certain actions subscribers have taken within your website. Think about when you visit certain pages on Amazon, for example, and the resulting emails you get to draw you back into the purchase process. (Retail is an easy and powerful example, but the same idea applies across industries.)

This could be simplistic if you have a small number of products or services. Businesses with large portfolios may want to dive into more advanced segmentation models.

Advanced segmentation

More advanced segmentation questions might detail individual audience member actions. Ask questions like:

• Based on historical data, when is this subscriber most likely to open an email?
• What date did this subscriber sign up for your mailing list?
• Does this subscriber often bounce after clicking through to your website?
• Does this subscriber delete all of my emails? Is there any value in marketing to her?
• How many times has this person visited the website?
• Does this subscriber respond better to different headlines than another subscriber?

If you can dream it, you can build it into your email list segmentation. The goal is to return more and more personalized emails to your audience, increasing the likelihood that what you’re sending speaks directly to them.