Rate Limiting (also known as push throttling) allows you to control the rate of push notification sends. This is intended to spread the load over your servers—so that you don't exceed your server-side capacity (and potentially crash your site).
Keep in mind, this is different from frequency capping—which is intended to limit over-messaging your users. We recommend using both Rate Limiting and Frequency Capping together—especially if you're running recurring campaigns.
You'll have the option to limit your messages at the Scheduling stage of building a Push message. You can throttle both One Time messages and Automated messages. For both options, check under the Advanced Delivery Options header at the Scheduling stage.
Rate Limiting is as simple as checking the Limit the number of messages delivered per minute check box. Fill in a limit for the number of messages your server can handle per minute. If you don't know, it's best to check with your developer/IT team. Continue scheduling your message as you normally would.
Users might receive a message at both the end of one recurrence window and the beginning of the next if the estimated time-to-send exceeds this window.
If a user receives a message at the end of the first send cycle and the beginning of the next for something like a daily recurring campaign, they’ll be over-messaged because the same message is received twice in a short timeframe. For this reason, we recommend also using the Frequency Capping feature (ie, limit the number of messages a user can receive within a given time period).
After you've set your rate limit, you'll see some additional metrics populate—specifically estimated audience size, and the estimated time until all messages are sent. Send time is just the total estimated audience size divided by the number of messages you're sending per minute.
We'll make sure to note that a message has been throttled on the True Impact report. This way you can better understand open rates and success rates of your push messaging campaigns.
If you've got more questions about Rate Limiting, we've got answers. Check the below resources, and if you don't see your question answered, give us a shout in the support inbox.
A: It's best to check with your IT team or systems administrator to determine server capacity—they can give you a suggestion on how many messages per minute your servers can support.
If you’re sending a message that you expect will create high demand on your website or app (like a highly anticipated product launch), we recommend you stay conservative with your send rate to maintain stability.
Q: Why is Estimated Audience Size coming up as zero when I select a limit to the number of messages delivered per minute?
A: Go back to the Audiences step of your messaging campaign to make sure you’ve selected the correct audience. Confirm that your selected Audience has populated with an audience size and that they are the correct audience to receive your message type (ie, a push message shouldn't be sent to an Audience that doesn't have push enabled).
If you need additional help troubleshooting the calculation of your Audience check out our help article.
A: If the estimated time is blank or unavailable, there may be an issue with the Audience size. Since the estimated time to send is directly associated with your Audience size estimates, you should troubleshoot your Audience to resolve the issue. Follow the steps in the question above to troubleshoot.
A: Yes, Rate Limiting is available in both One Time and Recurring campaigns. Keep in mind, when setting a send rate, confirm that your audience size and estimated send time will work within the time frame of your recurring campaign. For example, if it will take your message 16 hours to deliver to your entire Audience, but the recurring campaign triggers every 12 hours, you'll want to adjust either your Rate Limiting or the frequency of your campaign.
Check out the note above for more information about using Rate Limiting in recurring campaigns.