Sep 26, 2:17 PM EDT
Thanks for your patience as we’ve looked into this.
I was able to reach out for more clarification as to what happened here.
The information that controls the Send Time Optimization is based on the information we receive about the subscribers being sent the campaign from every audience they’re on in MailChimp.
This information constantly updates, so the results of enabling this at two different time periods, even within 24 hours, can differ based on this information.
I’ve had this ticket escalated to confirm, and from what we’re seeing, the Send Time Optimization is functioning as intended.
Thank you for that answer and your relatively speedy customer service on this complex issue. 🙂 I would offer up for consideration that this answer means to me that while it is functioning as intended, Mailchimp’s intention is flawed.
First, there no logical reason for two send times on the same day to both be optimal. Optimal means best. Both a 9am send and a 7pm send on 09/26 can’t be equally optimal – unless I guess of course if there’s no actual difference in optimization which would make the function irrelevant. If that’s what the data is telling you, then the function of data analysis for the purpose of optimization seems wrong to me.
Second, if the optimization can be so dramatically swayed by a 12’ish hour time delay, then that’s also a concern. I would expect a more firm “optimized send time” conclusion over a better period of time that would average out just such a fluctuation as caused by any single 12 hour period.