How to increase flow open rates

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Learn best practices around improving open rates for flows to help your truly business grow. Open rates measure customer engagement and monitor your deliverability and performance. That said, open rates will vary between flows and campaigns, due to the fundamental differences between campaigns (one-time sends) and flows (automated sends triggered by customer actions). 

Note this article specifically focuses on flow emails only, as open rates are not available for SMS in Klaviyo.

What is open rate?

Your open rates show how often recipients open your flow emails. 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.

Why open rates matter

Open rate is a key deliverability metric. If your open rates suffer over time, then your sender reputation will also diminish and inbox providers (e.g., Gmail, Yahoo, Hotmail) will begin sending your emails to spam. As a result, fewer people will see and open your messages, thus lowering your open rates and revenue from email. Meanwhile, 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 and engage with your marketing content, they are more likely to purchase.

Flows generally have a higher open rate than campaigns, with welcome series, abandon cart, browse abandonment, and post purchase/thank you flows seeing around 40% open rates. This will vary, however, depending on the flow; for example, a sunset flow that has the purpose of either re-engaging or suppressing unengaged audiences will likely not see as high of open rates.

How to increase flow open rates

The following are key strategies to increase flow open rates:

  1. Target your flow message
  2. Optimize subject lines
  3. A/B test your flow emails and branches
  4. Choose the best send time, delays, and message frequency

1. Target your flow message

It is crucial to target your flow emails to the most relevant audience. You can do so via flow filters as well as conditional and trigger splits. Flow filters are evaluated alongside the flow trigger itself to only let certain people into a flow. You can use filters to target a specific behavior or group of people, and they will ensure that only people who qualify will move through your flow.

A conditional split creates two paths in a flow so that you can curate what messages your audiences will receive, tailoring your content to align with characteristics about your recipients (e.g., their gender, purchase history, location, interests, etc.). For instance, in a welcome series or abandoned cart flow, you can split based on whether someone has purchased from you before, allowing you to target your offers and messages around who is or is not already a customer.

Example of a flow using a conditional split

For metric-triggered flows you can also add a trigger split. This split will create two flow paths based on characteristics of the flow metric. For example, for an abandoned cart flow triggered by Started Checkout, you can add a trigger split around cart value and curate your flow pathways so that high-value cart abandoners and lower-value cart abandoners receive different discounts or incentives to purchase.

2. Optimize subject lines

Always aim to send content that your audience wants to receive and use subject lines that entice them to open. As a general rule, be clear, concise, and compelling.

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

To optimize subject lines, you should:

  • Have a clear call-to-action (CTA)
    Every subject line should have a clear CTA informing the recipient of an action they need to take. Moreover, since flows are triggered by a customer action and often expected, your subject lines should be informative and align with your customers expectations and necessary next steps. For example, when crafting a subject line for an abandoned cart flow, your CTA should remind customers of the item left behind and spur a purchase. Consider offering a discount or a sense of urgency to capture their attention (e.g., “finish checking out before our sale ends”).
  • 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. For example, in your welcome series emails, you can add a sense of familiarity and community by including the recipients name as you welcome them to your brand (e.g., “thanks for joining Ashley” or “welcome to the community John”).
  • Include a sense of urgency (when applicable)
    Consider communicating urgency with a time limit (e.g., “your shopping cart is about to expire”). That said, only add urgency when applicable to the message, such as for an expiring shopping cart, browse abandonment deal, or a VIP rewards program invitation reminder.

 For subject line strategies that are flow specific, head to any of the following blog posts:

3. A/B test your flow emails and branches

A/B testing allows you to compare the performance of different copy, subject lines, flow pathways, and more to see what emails result in the highest open rates. As you monitor your results, the variation that performs best can inform your future design and sending choices. For flows, you can test specific emails as well as entire flow pathways. For more guidance, learn how to A/B test flow emails and how to A/B test flow branches.

For example, you can test two flow pathways and have one variation that sends an email one day after your first send and another that sends an email three days after your first send, this will give you insight into how frequently your audience wishes to receive communication. Similarly, you can test two different subject lines, such as one highlighting an incentive versus one adding a sense of urgency to gauge what content your audience responds best to.

Example of an abandoned cart email with two variations for testing

4. Choose the right send times, delays, and message frequency

Keep in mind that your recipients likely live in different regions and will thus be in different timezones. It is thus best practice to 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.

As mentioned above, you can A/B test flow branches to gauge what time your audience is most likely to open your flow emails. You can test the time of day that they receive your messages (e.g., 10 am versus 3 pm), the delay (e.g., 1 day versus 2 days after a previous send), and the frequency of messages they receive (e.g., two emails in one week versus three emails in one week). Use the results of your A/B test to adjust your flows and align with what variations prove most effective.

Example of a flow with a yes or no conditional split and subscribers waiting 1 or 2 days

Monitor your flow open rates

It's important to consistently monitor the performance of your flows, keeping track of not only open rates, but also all deliverability metrics that affect your sender reputation. You can do so in the associated flow analytics overview report for each of your flows. When you see a dip in open rates, readjust your sending strategy to promote business growth and avoid damaging your sender reputation.

For further flow analytics, build out custom reports, and in particular a flows performance report, to focus on your open rate trends over time. You can also compare your flow data to that of industry trends and companies similar to your own in the flow performance page of benchmarks.

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