Days since First Order

Days since First Order answers the question - how long did it take for a customer to place a 2nd, 3rd, etc. order (on average.)

• How many days did it take for the nth order since the first order
• It's always from the first order, not from the previous order (that'd be interesting too)
• Counter-intuitive part: It depends on the number of orders, so you'll see the average can be lower for the 3rd orders than for the 2nd if fewer customers placed 3 orders and did it faster than the majority of 2nd orders.
• Indicates when is a good time to nudge customers by email. If on average it takes 45 days for a second order, it's good to email customers who haven't repurchased yet around that time!

For the Days since First Order, it’s important to note it’s the average days only for the customers making subsequent purchases. So if the repurchase rate is low, it might not be representative enough of what a good frequency looks like.

For example, if the second order comes within 39 days, but if I were to run a campaign, I’d A/B test sending emails 35-55 days after the first purchase and see which one converts best.

More generally, it’s good to take the average for about 6 cohort months, by ignoring the older cohorts which had too much time to skew the data and the two most recent cohorts which are also too recent.

This metric allows you to analyze when to send reminder emails to encourage repurchase. You are able to look at when does it take on average for customers to come back and place their second order.

Is it because you are sending a notification right before, or do you want to try to send it earlier to impact the numbers?

Also, it can be helpful to think about causation - are they coming back because you are sending a note, or do they run out of your product or a combination?