Is it better to send out our campaign in the morning or in the afternoon? To answer this question, we did an experiment: we sent out 12 identical campaigns at a ~2-hour interval in one day. Each campaign was sent to 1200 emails. All 14400 emails are from the same country and they are randomized put into the 12 campaigns.
The sending time is in EST – Eastern Standard Time. The recipients are in EST, CST, MST, and PST.
Here we plot the click rate (%) as a function of sending time. We can see that there is no obvious best sending time. Whether you send in midnight, or in the morning, or in the afternoon, or in the evening, the click rate does not change in a systematic manner. So we can feel free to send our campaign at any time.
Click rate as a function of sending time
What about the open rate? Like the click rate, the open rate does not systematically change. There is no obvious best sending time to maximize open rate.
Open rate as a function of time
Lesson Learned:
- There is no obvious best sending time in a day to maximize the click rate.
- There is no obvious best sending time in a day to maximize the open rate.