Returning Customer Rate is a tricky metric. In most of the industry it is the same as Repeat Purchase Rate except Shopify considers it something differently.
In Shopify, the Returning Customer Rate is the measurement of customers who bought a second time in a given period of time.
While it's similar to Repeat Purchase Rate, Repeat Purchase Rate requires the initial order and second orders to be fully within the time. Returning Customer Rate on the other hand allows for the initial order to be outside the period of time (details here).
Returning Customer Rate can be useful when you're looking at a narrow date range of behavior data, especially if you compare it to your overall Repeat Purchase Rate. This will tell you if customers are ordering again more or less.
Returning Customer Rate has nothing to do with returning customers.
Eric Davis
Learn what your customers are actually doing instead of just guessing
One of the best ways to build a sustainable business starts by getting your customers to come back. Mastering that simple process can be difficult, but builds a lifelong business.
Repeat Customer Insights can help you understand your customer's behavior. With its collection of behavior reports, you can see what they're actually doing instead of guessing and having your efforts fall flat.