You know the spiel. Email continues to generate the most ROI of any marketing channel. It allows you to connect with your customers on a one-to-one basis.

For these reasons, many marketers are understandably focused (read: obsessed) with growing their email lists. While the size of your list is important, it is not the only factor to think about as you build and grow your email program.

Here are three additional elements of an email marketing strategy to consider other than email list size.

1. The quality of your email list matters.

How are you building your email list? Where are you getting email addresses? Are you cleaning your list periodically?

If you’re sending to users who haven’t clearly opted in to your email, if you aren’t cleaning out your lists, or (gasp) you bought or borrowed your lists from a third party, then you’re targeting people who don’t want to hear from you.

While such actions may make your list longer in the short term, these mistakes will most likely cause your bounce rate to increase. You’ll likely get dinged by IPs and email providers, your sender reputation could plummet, and you’ll probably see little return on your investment. You might even be undermining your brand and hurting your business.

A large but low-quality list can’t hold a candle to a smaller but carefully and intentionally built list that earns high engagement from users.

Here’s how to build an email list that is high quality and primed for engagement:

• Only send to subscribers who have opted in to receive email communications from your brand. You may even want to go with a double opt-in process that ensures subscribers are knowingly and willingly asking to receive emails from you.

• Make it easy for potential subscribers to opt in by taking advantage of all your active channels. Include a conspicuous subscribe option on your website. Invite your followers on social media to also subscribe to email. When you attend conferences or networking events, mention how to subscribe in your presentations and handout materials.

• Make it clear what subscribers will gain by joining your list, whether it’s exclusive content and offers, early access to products, or special deals.

2. How you segment your email list matters.

How you segment your list, even if you’re still focused on growth, has a powerful effect on engagement. Successful email marketing boils down to reaching the right person with the right message at the right time.

If you are sending the same content to everyone on your list, then you’re missing opportunities to build stronger engagement through personalization.

In marketing, personalization is the difference between walking into a hotel and walking into your own home. Where do you feel more comfortable and in control? Email segmentation allows you to tailor content so that recipients feel listened to and valued.

And it shows. According to DMA, 77% of email marketing ROI generated in 2015 came from segmented, targeted, and triggered campaigns.

There are any number of ways to segment your email lists, and the best method for your brand will depend on your audience.

Here are a handful of ways to consider segmenting your email list:

• By buyer stage. Customers at different stages in the buying process will be looking for different information.

Are you an online retailer with a quick buying process? Send complementary product recommendations to customers with recent purchases or a discount offer to a customer who hasn’t engaged for a while.

Are you a B2B brand with a drawn-out sales process? Segment subscribers by stage, from awareness to retention, and send content recommendations, trial offers, and product tips to keep prospects and customers engaged.

• By demographics. If it makes sense for your offer and audience, segmenting by age, geography, or education can help you target different subgroups of your audience likely interested in different aspects of your business.

Here is a good place to point out the pitfalls of not segmenting your list. Imagine you live in Florida and a brand sends you “10 Tips for Protecting Your Vehicle from Cold Winter Temps” or that you’re a single bachelor and you see “Life-Saving Advice for Every New Parent” in your inbox. Brands that mistakenly send irrelevant content come off as out of touch at best, offensive at worst.  

• By industry. Many B2B brands market their products or services to a range of different industries. Even if the product or service is the same, different industries may put it to use in different ways.

Segmenting based on industry lets you tailor content so that it is relevant to all your recipients instead of only a fraction every time you send.

3. The quality of your email content matters.

It doesn’t matter how lovingly you’ve curated your email list if the content you’re sending is subpar.

Even as you focus on growing your list, don’t forget about engaging and retaining. That means delivering valuable content to the right subscribers at the right time.

Here are some quick ideas for creating high-quality email content:

• Make it exclusive. In this day and age, handing over your email address is an act of faith. Reward your subscribers for trusting you, and give them access to exclusive content. This could be email-only or early access to special offers, white papers, products, or beta tools.

• Look at your data. Mine your data to find out what kind of content people are already engaging with, and then give them more of it. Sound simple? It is.

• Make it interactive. Quizzes, videos, games, and gifs can pull your audience in and give them a way to engage with your content.

Building a large email list is a critical part of any email marketing strategy, but it’s not the only one. You also have to consider the health of your list, how you’re segmenting it, and the content you’re sending. Check out the Email Design Toolkit to discover more ways to build better email journeys for your customers.