STO: Important usage information

For audience members with optimal send times within the send period, they will move from the Send time optimization stage to the next Send email campaign stage along the “With STO Data” path at the optimal send time at the top of the hour. For example, audience members with optimal send time of 14 for that day will move from the Send time optimization stage to the Send email campaign starting at 2pm. Note: There is an exception for the initial optimal send time(s).

When the audience moves to the Send time optimization stage, the process of identifying the optimal send times for each audience member and segmenting them into optimal send time groups do take time. This process time varies based on the size of the audience itself. As a result, the audience members who have optimal send times that are the same as the time of entry into the Send time optimization stage may not necessarily move to the Send email campaign stage at the top of the hour. Instead, it will move the audience members as soon as the process completes. For example, if the audience moves to the Send time optimization stage at 9am and the process of identifying the optimal send times and segmenting the audience into groups takes 20 minutes, then the group with the optimal send time of 9am will not move to the Send email campaign stage until 9:20am. The remaining groups will move at the top of the hour based on their optimal send times.

Tip: If you notice that the process time is consistent, you may consider entering the audience into the Send time optimization stage earlier to compensate for the delay for the initial optimal send time group. For example, it the process time is 20 minutes, instead of entering the audience into the Send time optimization stage at 9am, enter them at 8:40am so the group with the optimal send time of 9am will move to the Send email campaign stage closer to the top of the hour.

When the audience members enter the Send time optimization stage, it will take some time to look up the optimal send times for each user and assign them to optimal (hourly) send time groups. The actual time depends on the size of the audience members that enter. Sometimes the process will take so long, the optimal send time group will not be created for the hour when the audience members entered. As a result, the send period will begin the next hour.

For example: Let’s say your desired send period is Monday, 9am through Tuesday, 8am. The size of the audience members is so large that the optimal send time lookup takes a long time and the optimal send time group for Monday, 9am is not created. The Send time optimization stage will then delay the send period by 1 hour to Monday, 10am through Tuesday, 9am.

Tip: Currently, it takes roughly 40 minutes for the Send time optimization stage to process an audience member size of 10 million messages (10MM) to generate that first optimal send time group. To prevent the desired send period from being delayed and hour, you can try entering audience members before the first hour of the send period. Do not enter your audience members more than 60 minutes earlier than your desired send period; otherwise, you may risk starting the sends earlier than expected.

For example: Let’s say the size of your audience members is 10MM and your desired send period is Monday, 9am through Tuesday, 8am. You can try to enter the audience members into the Send time optimization stage on Monday, 8:40am.

Please refer to the Send Period Delay Prevention example in the STO Programs section for additional guidance.

As you may know, moving from one stage to the next stage in Program takes time. The original STO Program design prior to the introduction of the Send time optimization stage was complex, raising the possibility of delays that result in the email campaign not being sent at the optimal send times. To compensate for the delays, a special SQL was written to offset the optimal send times so the audience is sent the email campaign before the actual optimal send times so it’ll arrive in the inboxes at the intended optimal time.

With the Send time optimization stage and its ability the move audience members to the Send email campaign stage at the top of the hour, offsetting the optimal send times are no longer needed or available.