Send Time Decisioning

Send Time Decisioning is an Iterable AI feature that helps send email and push notifications when your contacts are most likely to engage with them. For each recipient of a campaign, Send Time Decisioning analyzes historical engagement behavior and selects an optimal, per-person send time.

# In this article

# How Send Time Decisioning works

As you use Send Time Decisioning (formerly, Send Time Optimization - STO), remember that:

• Send Time Decisioning optimizes send times based on project-specific data. It does not analyze cross-project data for the same contact.

• Send Time Decisioning is enabled for a single blast campaign and only applies to the campaign you're actively editing.

• For predictions, Send Time Decisioning considers historical engagement data (such as when users open messages) in order to predict optimal send times.

• While Send Time Decisioning predictions are made in the user's timezone, Send Time Decisioning Insights metrics are reported with all times mapped to the project's time zone for display.

• Iterable updates Send Time Decisioning machine learning models once per week.

• Although Send Time Decisioning doesn't guarantee higher engagement, it may improve the Email Open Rate, Email Click Rate, and Push Open Rate campaign metrics.

• Send Time Decisioning accounts for Apple's Mail Privacy Protection feature.

# General send time considerations

Send Time Decisioning sends campaigns as described here:

• Send Time Decisioning is available for both email and mobile push blast and triggered campaigns, email and mobile push send tiles in a journey, and as an email experiment.

• Optimized send times always fall at the top of the hour.

• When an optimized send time increases through the specified window and peaks after the window ends, Send Time Decisioning sends the message at the end of the send time window.

• If a user has less than three months of active user engagement data, and Iterable can't determine an optimized send time, messages are sent at the campaign's configured send time (even if Send Time Decisioning is enabled).

• A rate limit associated with a campaign may cause a campaign to send some messages outside of the Send Time Decisioning window.

• If you turn on Quiet Hours and Send Time Decisioning for a campaign, and the ideal send time for a user falls within your Quiet Hours window, your send won’t be optimized—it will be held until the Quiet Hours window ends. For example, if Send Time Decisioning selects 5:00 AM as the ideal send time, but Quiet Hours is set from 9:00 PM to 9:00 AM, the campaign will be sent at 9:00 AM.

• If a campaign-triggering API call specifies a specific send time (sendAt), Iterable doesn't use Send Time Decisioning for that send.

# Send time considerations for journeys

The following additional considerations apply for journeys that have Send Time Decisioning enabled on an email or push journey tile:

• Send Time Decisioning sends a message based on the Complete Within value you provide, starting when a user enters the journey. For example, if a user enters a journey at 7:05 a.m. and the send is scheduled to complete within 5 hours, Send Time Decisioning will determine the optimal time for the user between 7:05 a.m. and 12:05 p.m.

• Disabling a journey that has Send Time Decisioning enabled doesn't prevent queued messages from being sent.

• If a user satisfies exit criteria in a journey that has Send Time Decisioning enabled, the message will still be sent at the optimized time chosen by Send Time Decisioning, even though the user exited the journey.

# Send Time Decisioning and experimentation

Keep these considerations in mind when using Send Time Decisioning with experiments:

• If you're running an experiment with a campaign that also has Send Time Decisioning enabled, ensure that the Send Time Decisioning window is at least six hours longer than the experiment duration.

  For example, you should not specify a Send Time Decisioning window of eight hours and an experiment window of three hours.

• You can use Send Time Decisioning with or without a Send Time Decisioning experiment. Without one, Iterable uses Send Time Decisioning for all of the campaign's recipients. With an experiment, Send Time Decisioning uses a 50/50 control/variation split for Send Time Decisioning experiments. This isn't adjustable.

  For more information, see Creating a Send Time Decisioning test.

# Send Time Decisioning Insights overview

After you've sent messages with Send Time Decisioning enabled, you can learn a lot about how your optimized messages are performing by reviewing Send Time Decisioning Insights. You can:

• Learn about the overall distribution of messages (by percentage or by count) that were sent using optimized send times over time.

• Learn about overall engagement for the selected period of time.

• View click rate lift and open rate lift metrics to learn how a treatment group (those who received optimized messages) performed when compared to a control group (those who received only unoptimized messages).

• View the top and least preferred send windows for messages for the selected period of time.

• Learn how many optimized users were sent messages for a given channel (email or push), along with the size of the audience who received optimized sends and the total number of sends.

• View details about the volume of messages sent for a given day or time of day.

# Review Send Time Decisioning Insights

To review how your message sends are being optimized:

1. Go to Insights > Intelligent Insights to open the Send Time Decisioning Insights page.

2. At the top of the page, filter message sending optimizations to display data for the past 30, 60, or 90 days. A 30-day view allows you to focus on the impact of a specific campaign, while a 90-day view may help you evaluate how well optimizations are performing more broadly.

3. From View Trends By, specify whether you want to view data by Percent or by Count.

4. In the Send Time Distribution Over Time chart, view how optimized messages were sent for the specified time periods, sorted by weekday and weekend, and also by morning, afternoon, evening, and night.

   

5. In Overall Performance, view various lift metrics to learn how a treatment group (those who received optimized messages) performed when compared to a control group (those who received only unoptimized messages).

6. In Breakdown by Channel, click the tab for the channel you want to view (email or push). You can view a detailed analysis of lift, engagement, or delivery metrics for optimized sends for the selected channel and message type.

   

# Want to learn more?

For more information about some of the topics in this article, check out these resources. Iterable Academy is open to everyone—you don't need to be an Iterable customer!

Iterable Academy

• Product Bite: Send Time Optimization

Support docs

• Optimizing Campaign Delivery
• Increasing Engagement in Journeys