5 Do's and Don'ts For Creating Effective Email Lists Keep your subscribers engaged month after month by creating content they're really want to read.

In his book Success Secrets of the Online Marketing Superstars, Mitch Myerson introduces you to 22 innovators who have redefined the developing landscape of online marketing. Learn how to master proven strategies, avoid costly mistakes and grow your business. In this edited excerpt, contributing author and founder of WPBeginner Syed Balkhi offers some helpful advice so you can create emails that get opened rather than ignored.

If you've created a blog, started a social media account, or even read a few articles online, you'll almost certainly have noticed that people reading online have short attention spans. There are several reasons for this—including the fact that it's tougher to read on a screen than in print, and that many websites are chock-full of distractions.

When you're communicating by email, you may have a slight advantage as there's less visual clutter in most people's email interfaces than on many websites, but you'll still need to compete with dozens, perhaps hundreds, of other emails for attention.

Here are five quick tips to help you get your email content right:

• Spend time crafting your subject line, just as you'd carefully craft the headline for a sales page or the title for a blog post.
• Get the frequency of emails right. For many industries, daily is too much—your readers will feel inundated, and may quickly unsubscribe. On the other hand, once every three months is usually too little—people will forget who you are and may trash your email or even mark it as spam, having forgotten they ever signed up for your list.
• Make your content truly worth reading. Ask yourself, "Would I open this email?" You might want to think about the questions or problems that your readers are likely to have and create content to address those.
• Don't go over the top with design. Some marketers prefer to use plain text; others use flashy templates. While a bit of formatting helps make your emails attractive and readable, don't make the whole thing rely on images—these won't necessarily render correctly (or at all!) in everyone's email clients.
• Create compelling subject lines. The biggest challenge you face is often simply getting your email opened. Some marketers will go to almost any lengths to entice clicks (I'm sure you've had your share of dodgy emails telling you that you've won something), but unless you want a lot of spam complaints and unsubscribes, it's best to craft subject lines that clearly reflect your email's content. On the flip side, a very bland, boring subject line will often mean your email gets ignored.

If you're new to email lists, it's easy to make mistakes. The following are some very common and understandable ones, but they can lose you a lot of subscribers—and money.

Mistake #1: Emailing irregularly. You may start your email list with great intentions, planning to send a weekly tip plus a longer monthly newsletter, but if months slip by without emails—only to be followed by a flurry of messages when you suddenly carve out some time—you'll be confusing and quite possibly annoying your subscribers.

Solution: Work out a mailing schedule and stick to it. Weekly, every other week, or monthly can all work well. If you decide to increase or decrease the number of messages, do so gradually (don't suddenly jump from emailing weekly to emailing daily).

Mistake #2: Forgetting to promote your email list. When you launch your email list, you'll probably find yourself writing about it on your blog, encouraging your social media followers to sign up, getting other entrepreneurs to promote your opt-in incentive, and so on. As time goes by, though, it's easy to forget to actively promote your list—meaning that growth slows to a trickle.

Solution: Every few months, plan a new round of promotion. Write guest posts, update your opt-in incentive, or even encourage readers to forward your emails to friends (make sure you include instructions in your email footer along the lines of "If you received this from a friend, you can join us here ...").

Mistake #3: Ignoring the "snippet." Some email clients, like Gmail, show a short preview of emails alongside the subject line. Unfortunately, many companies ignore this—leading to text like "Problems viewing this email?" or "ABC Corp logo" or worst of all, "Use this area to offer a short teaser of your email's content" appearing as the snippet.

Solution: Make sure the text at the start of your email is useful and adds to your subject line. If you're using plain text, you probably don't have a problem here, but if you're using a template and it has a special space for this text, be very careful to update it each time.

Mistake #4: Getting upset by unsubscribers. Every time you send out an email to a list, some of your readers will unsubscribe. While this is understandably disconcerting, you don't need to panic that you're doing something wrong. The fact is, some people will inevitably be clearing out their inboxes and reducing their subscriptions—it's nothing personal.

Solution: Look on the bright side: If someone unsubscribes, they were probably never going to buy from you in the first place—and now you're no longer paying to have them on your email list!

Mistake #5: Never testing emails. Your email service provider should allow you to split-test emails by segmenting your list and sending out slightly different versions—perhaps using different subject lines, or with and without personalization. If you never do any tests, you'll never know if a small tweak could've resulted in a much more effective email.

Solution: It's an especially good idea to test emails that go out repeatedly, rather than as a one-off broadcast—e.g., if you have an autoresponder series that begins whenever someone signs up for your newsletter. Any promotional emails are also great ones to test, as a small increase in open rate or CTR (click-through rate) can have a significant impact on your profit.

For more information or to access exclusive audio interviews with superstars from this book visit OnlineMarketingSuperstars.com.