Want better email revenue? Send late at night!

Experian found that emails sent between 8pm and 12am generated higher open and clickthrough rates, more transactions, larger orders, and greater revenue per email than emails sent during any other time of day—and by a significant margin.

The advantage of nighttime sends in revenue per email was especially noticeable: Emails sent between the evening time slot averaged a return of 48 cents per email, more than triple the overall average of 14 cents per email. The next best-performing time slot was even later: from 12am to 4am; those emails only generated 22 cents per email on average, while the least lucrative time to send was between 12pm and 4pm, when senders only averaged a return of 15 cents per email.

Overall, unique open rates increased from 14.4% in Q4 2011 to 16.3% in Q4 2012, while clickthrough rates, transaction rates, and revenue per email all held relatively steady. The dollar value of the average order increased from $160.99 to $180.25.

As email marketers pay close attention to the times when their campaigns get the best ROI, they also must begin factoring in the device on which consumers are opening their messages. Smartphones and tablets are playing an increasing role in consumers’ off hours, and many of these emails will see clicks from mobile devices.