Optimal send time in scenarios and campaigns
When you run a campaign or scenario, every customer receives the message at the same scheduled time — regardless of when they're most likely to engage. Optimal send time (OST) changes that: the platform delays each customer's message until their personal peak engagement hour, calculated from their own campaign history. Delivery timing runs automatically, with no extra segmentation or manual scheduling required.
Built-in OST vs. standalone OST predictions
Bloomreach has 2 separate OST features that serve different purposes:
- Built-in OST (available in the Scenario Wait node and campaign Schedule setting) uses self-contained logic to calculate and apply optimal timing automatically. It can't reference or select saved prediction templates from Analyses > Predictions.
- Standalone OST predictions (Analyses > Predictions) calculate OST and store the result as an attribute on each customer's profile. Use this attribute for segmentation, filtering, reporting, and dynamic wait times in Scenarios via Jinja.
If you use custom events or webhooks (for example, custom SMS or custom push), built-in OST can't analyze those events. Create a standalone OST prediction using the Other channel option, map your custom events manually, then use the resulting profile attribute to drive timing in your Scenario.
Use built-in OST in scenarios via the Wait node, or in SMS and Email campaigns via the Schedule setting. To use OST with custom events or webhooks, see Built-in OST vs. standalone OST predictions above.
OST objective and packaging
OST optimizes for clicks by default. The previous "optimize for open vs. click" selector has been removed because open event data can be unreliable. When click data is insufficient, OST falls back to opens.
In scenarios, OST can be calculated per messaging channel (email, SMS, MMS, RCS, push, or all channels). The channel selector in the wait node requires the Loomi AI Journey Orchestration package. Without it, the Wait node defaults to all-channel behavior—using engagement data across all channels—available with the Loomi AI Audience Optimization package.
Send strategy
The send strategy controls how the system handles timing when a customer's OST falls outside your campaign window. Choose based on whether you need a hard delivery deadline or a flexible window.
| Use | When |
|---|---|
| Send within a time window | You want to limit how long a customer waits, but don't need delivery by a specific clock time. |
| Send before a specific local time | You need a hard deadline — each customer must receive the message before a set time, in their own time zone by default. |
Send within a time window
Use this when you want to set a maximum wait time rather than a specific delivery deadline. For example, a daily newsletter scheduled for 10 AM with a 12-hour maximum wait reaches each customer at their preferred time, but no later than 10 PM.
The message is sent:
- At the customer's best time within that window.
- Immediately, if no better time exists within the window.
- Immediately, if the best time has already passed.
Send before a specific local time
Use this to guarantee delivery before a fixed local time — for example, a daily promotion that must arrive before 20:00.
To configure:
- Set a "send before" time, for example,
20:00. - Configure a default time zone.
Use customer profile time zone when available is enabled by default to respect each customer's own time zone. Disable it to apply a single time zone across all customers instead.
The message is sent:
- At the customer's best time before the deadline.
- Immediately, if the best time has passed.
- At the deadline, if no earlier time is available.
Configure OST for scenarios
- Go to Campaigns > Scenarios, click + New scenario, and continue with + Create scenario.
- Configure your scenario.
- In the Nodes list, scroll down to Operator and add the Wait node.
- Double-click the Wait node, select Optimal send time prediction. This uses built-in OST logic — it doesn't reference saved prediction templates from Analyses > Predictions. Select the messaging channel to determine which campaign data is used to calculate OST. The messaging channel selector requires the Loomi AI Journey Orchestration package — without it, OST uses all-channel data by default.
- SMS / MMS / RCS
- Push / mobile channels
- All channels — uses engagement data across all campaign channels
- Select the send strategy from the following:
- Send within a specific time window: Sets the maximum wait time.
- Send before a specific time: Sets a "send before" time and a default time zone. You can also enable Use customer profile time zone.
- Save and Start your scenario.
Configure OST for campaigns
- Go to Campaigns > Email or SMS Campaigns, click + New Email/SMS Campaign.
- Select a template or continue with a blank one.
- Configure your campaign.
- Go to the Settings tab.
- For the Schedule setting, select Optimal send time prediction.
- Select your send strategy. Enable Use customer profile time zone to send at the right local time for each customer. If a customer's time zone isn't set in their profile, the default time zone applies
- Save and Start your campaign.
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