The Keys to Writing Reminder Emails That WorkWhen done right, reminder emails can be the perfect prompt to get a subscriber to take action.

Inemail marketing, the secret is to send timely, targeted and valuable messages that people want.

Easier said than done.

The cold reality is that not every email you send is opened. The average open rate is around 20 percent across all industries. That percentage doesn't really tell the complete story either. Unless you really dig into your metrics, it's unclear which 20 percent is opening your emails. It's also likely it's not the same 20 percent opening your emails every time.

One way to give your emails a better chance of getting opened and read is to send reminder emails. Even better, sending reminder emails personalized for each subscriber.

Here's an example. My wife and I have been REI members for several years. One of the perks of membership is an annual dividend -- a share of the co-op's annual profit. We recently made a few big purchases that were large enough to earn a decent-sized dividend ($73.34 to be exact).

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REI sent us a nice direct mail piece with a big "dividend coupon." I glanced at it, thought about going to REI to redeem it and then it vanished. Like most mail in our house, it just seemed to disappear.

Then, a few weeks later, I received this email from REI. The subject line read: Remember - You have $73.34 to spend!

I opened the email. I clicked the "Shop Online" button. Seven minutes later I had a new bike helmet and a few items for my children.

This email worked. I opened. I clicked. I purchased. If you are on the email marketing team at REI, that's called a win-win-win. If you are in charge of revenue at REI, you should also be happy with this result.

But why was it effective? Let's break down the emaill:

From name:丽Gearmail. It's a name I recognize and trust. It's an email I get regularly and one that consistently delivers on its promise of value.

年代ubject line:Remember - You have $73.34 to spend!Leading with the word "remember" did just that, it reminded me I had something important to review. Adding the amount of the dividend in the subject line helped the email stand out in my cluttered inbox.

Email copy:The headline read, "REMEMBER TO SPEND YOUR REI DIVIDEND." All caps. White text on a green background. It stood out. The rest of the copy was simple, direct, and actionable:

Because you're part of the REI co-op, you've earned a dividend.

Find something to spend your dividend on—you still have $73.34. Shop now

You can redeem your dividend in store, online or by calling 1-800-426-4840.

This was followed by two buttons -- "Shop Online" and "Find a Store" -- which were clear and easy to click on.

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While REI was not able to share specific details of this particular campaign, an REI spokesperson told me this: "We provide our members with as much information as possible to encourage them to use their dividend each year. We are testing new and different ways to share the amount of remaining dividends with REI members -- for example, through standalone emails or banners. This campaign is an example of one way we attempt to address any barriers that may be in place for members to redeem any of REI's membership benefits."

Interpret that as you may, but my take is this campaign is effective in nudging members to redeem unused benefits.

Emails like the REI example don't always have to remind members to spend unused dividends. Reminder emails can be for any action you want to nudge your subscribers about -- upcoming webinars, discounts on online courses, eBook downloads and so on.

An effective reminder email focuses on three components:

1. Subject line:While compelling, creative subject lines can be effective, when it comes to reminder emails, the more direct and actionable, the better. The goal is to have your subject line sufficient to remind your subscriber what they already know about (but may have forgotten).

2. Copy:Again, there is a time and a place for long, creative, cutesy copy. Reminder emails are not one of them. Focus on short, clear and concise copy. No fluff. Don't mince words. Tell your subscribers why you are emailing them and direct them to the call to action.

3. Call to action:As mentioned above, the copy should lead directly to the call to action -- a button, a link, or both. Don't make your subscribers have to hunt for the action you'd like them to take. Make it simple. Make it easy. Make it obvious.

Not every email gets read. Sometimes your subscribers need that extra nudge. When done right, reminder emails can be the perfect prompt to get a subscriber to take action.

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