How to Increase Campaign Open Rates

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Open rates allow you to measure customer engagement and monitor your deliverability and performance. When you send a campaign that results in a critically low open rate, Klaviyo will alert you, prompting you to refine your sending habits. In this article, you will learn best practices around improving low open rates so that you can grow as a brand without harming your sender reputation.

This article specifically focuses on email only, as open rates are not available for SMS in Klaviyo. If you are interested in learning more about SMS performance indicators, head to Campaign SMS and MMS Benchmarks for guidance.

What Is Open Rate?

Your open rates show which recipients open your emails and at what rate this happens for each email you send. Below is the calculation for open rate in Klaviyo:

  • Open rate = the number of individuals opening your email divided by the number of recipients

With the release of iOS15, macOS Monterey, iPadOS 15, and WatchOS 8, Apple Mail Privacy Protection (MPP) changed the way that we receive open rate data on your emails by prefetching our tracking pixel. With this change, it’s important to understand that open rates will be inflated.

To see if your opens are affected, we suggest creating a custom report that includes an MPP property. You can also identify these opens in your individual subscriber segments.

For complete information on MPP opens, visit our iOS 15: How to Prepare for Apple’s Changes guide.

Why Open Rates Matter

If you continually email unengaged subscribers, your sender reputation will diminish and inbox providers (e.g., Gmail, Yahoo, Hotmail) will send more of your emails to spam. As a result, fewer people will see and open your messages, thus lowering your open rates and revenue from email. When people stop opening your emails, it's an implicit sign that they are no longer interested in receiving your brand content, and you should refrain from sending to these profiles.

Good sending habits and high open rates equate to a better sender reputation. Opened emails signify customer engagement and interest in your products. When people open your emails, they are engaging with your marketing content and are more likely to purchase. Moreover, the better your open rate, the less likely you are to end up in the spam folder.

A good open rate is 20% or higher; a great open rate is 25% or higher. For more information on what qualifies as good (and bad) for deliverability metrics, head to our article, How to Monitor Deliverability Performance.

How to Increase Open Rates

There are four key steps to increase open rates:

  1. Create engaged segments
  2. Create targeted subject lines
  3. Clean your lists regularly
  4. Choose the right send time

Create Engaged Segments

Engaged segments are key to successful email marketing. They inform you of who you should communicate with and update automatically with subscribers who meet the conditions you set based on the recency and frequency of their engagement. As you add conditions to make segments more specific, you’ll also gain insight into how to target them with relevant content that will receive higher open rates.

Let’s go through three steps to creating engaged segments that can increase open rate. First, create your segment, adding criteria around how recently someone engaged with your brand. Your segment definition should include: those in your main list, who either opened or clicked recently, or subscribed to your list recently. We recommend adding conditions to include anyone who opened or clicked your emails within the last 30 days, as well as anyone who subscribed to your main list in the last 15 days as a starting point.


Next, evaluate your segment’s performance and adjust the time range to either widen your audience or shrink it to a more engaged group. If your open rates are well above 20%, expand this definition to include those who have engaged with your emails in the last 60 days rather than 30. However, if your open rates fall below 20%, tighten this timeframe (e.g., to 14 days) until you identify your core engaged audience. Your segment criteria should align with your brand’s typical sending schedule as well; if you’re a daily sender, then your segment will look different from someone who sends once a week.

For further instruction, follow our 30-, 60-, and 90-day engaged segment strategy in our Guide to Warming Your Sending Infrastructure. Otherwise, create email frequency segments to decide who should receive emails daily, weekly, or monthly.

Finally, take segmentation to the next level by adding more specific criteria to your segment. This allows you to send personalized content that is relevant to someone's specific purchase history, interests, email habits, location, etc. The more personalized your emails are, the more likely recipients are to open them. Head to our Guide to Advanced Segmentation for inspiration.

Create Targeted Subject Lines

Once you have an engaged segment, create relevant emails for this audience. Refrain from overloading subscribers with unnecessary content; rather, send content that your audience wants to receive and use subject lines that entice them to open without sounding spammy.

Want to test out different subject lines or send times to discover what works best for your audience? A/B test your campaigns  to solve these key business questions and optimize your email sends.

As a general rule, be clear, concise, and compelling. To optimize subject lines, you should:

  • Have a clear call-to-action (CTA)
    For example, if your CTA pertains to a flash sale, make that obvious to engaged customers within the subject line of your email and add a sense of urgency to the deal. Meanwhile, if your CTA informs customers of a recent change to your company that requires them click into a link for more details or to update their account, be honest and informative, and cut out any unnecessary verbiage.
  • Be personal
    Add a recipient’s first name to your subject lines. This personalization leads to an increase in open rates 60% of the time. You can also align your content with specific profile properties you have collected about subscribers (e.g., local events, weather, interests, etc.) or common hopes and pain points that resonate well with your audience (e.g., “imagine yourself x years from now” or “we know you’re tired, so here’s a pick me up”).
  • Include a sense of urgency (when applicable)
    Consider communicating urgency with a time limit to an email offer within the subject line (e.g., “you have X rewards points that expire in 2 weeks” or “our sale ends in 48 hours”). That being said, only add this urgency when applicable to the message, such as for a flash sale or for a VIP rewards program reminder.

For more information on how to create successful email content, head to our course, Getting Started with Email Design

Clean Your Lists Regularly

It is crucial to clean your main subscriber list regularly to remove any unengaged, misspelled, fake, or spam email addresses that you may collect over time. Removing these unengaged and fake profiles will increase your open rates as you weed out any profiles who should no longer receive your messaging and who are having a negative impact on your deliverability. As such, this process can also boost your sender reputation in the eyes of inbox providers, like Gmail or Yahoo.

For information and step-by-step instructions on how to clean your lists, head to our Guide to List Cleaning.

Choose the Right Send Time

Keep in mind that your recipients likely live in different regions and will thus be in different timezones. For both flows and campaigns, you can send messages at a specific time within your recipient’s local timezone. If you do not, you risk sending too early or late at night, and your email may be ignored. You can also employ Smart Send Time which uses your business' data to find an optimal send time for your subscribers.

Monitor Your Performance

It's important to consistently monitor the performance of your campaigns and flows, keeping track of not only open rates, but the other deliverability metrics that affect your sender reputation as well. When you see a dip in open rates, then something is likely wrong with your email sends. You may need to readjust your messaging to resonate with your audience or update the conditions of your engaged segment. In either case, monitoring email outcomes allows you to avoid seriously damaging your sender reputation.

After sending a campaign, review the associated campaign analytics to see how well your emails perform and make adjustments to what segments you target what your email content includes. Also, build out any custom reports, particularly a Campaign Performance Report, to focus on your campaign open rate trends over time. You can also monitor this performance indicator in Benchmarks.

Additional Resources

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