Just to be clear, we’re talking about Smart Send Time, and not Smart Sending right? 
@jsappington - I can speak of only what we’ve encountered through some of our past client work, but we tend to think of Smart Send Time as just one of the tools to try to improve the engagement level of campaign emails if engagement (open/click) is low or declining.
- Because it does require a larger List (12,000 or more), by definition this is something we try only when a merchant has a sizable Lists where there’s enough confirmations.
- With a bit of intuition mixed in with the data science here, we propose to try Smart Send when the merchant has a strong bifurcated “coastal” audience or “international” audience (especially if they don’t split their marketing by regions).
- Some email campaigns are naturally more optimal for Smart Sending - specifically ones that are not time sensitive! Better yet, if there’s an evergreen campaign that is timeless (e.g. Staple Products, Educational Content, etc) you can repeat/retest the same campaign in the future to another cohort of subscribers to keep things as consistent as possible.
- Definitely some intuition or “gut” instincts to go along with the test - but the data might surprise you. In one instance I heard of, the optimal time was so unexpected (very late in evening, whereas the brand typically sends in the AM), they were surprised with the result, and started sending a few subsequent campaigns with the new optimal time (evenings) and it worked out well!