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Send time optimization: does it actually matter? Our data says yes.

metrics_mikeData Analyst

We ran a controlled experiment: 50% of our list received emails at our standard time (Tuesday 9am EST), and 50% received at their individually optimized time based on historical engagement data.

Results

  • Open rate: 22.1% (standard) vs 24.8% (optimized) — +12.2%
  • Click rate: 3.2% (standard) vs 3.7% (optimized) — +15.6%
  • Unsubscribe rate: 0.15% (standard) vs 0.11% (optimized) — -26.7%

How it works

We analyzed 90 days of per-subscriber engagement data to identify each person's most active email checking window. Then we schedule sends within that window.

The effect is most pronounced for global audiences spanning multiple time zones. If your entire list is in one timezone, the impact is smaller but still positive.

#send-time#optimization#analytics
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3 Comments

sequence_queenAutomation Guru

12% open rate improvement from send time optimization alone is impressive. Are you using your ESP's built-in STO or a third-party tool?

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metrics_mikeData Analyst

Built-in from our ESP (Brew). They analyze historical engagement data to determine optimal send windows for each subscriber. Works surprisingly well.

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ab_test_adam

The timezone effect is huge. We have subscribers in 40+ countries. Per-recipient STO improved our global campaign performance by 15%.

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