A one-time customer, also called a new customer, is a person or business who has only purchased once from your store.
They are important because they have shown the first behavior that makes them a customer. Before that time they were a visitor, prospective customer, or lead. All customers start out as one-time customers, a few might transition to a returning customer or repeat customer.
The vast majority of ecommerce customers are one-time customers.
Eric Davis
How do your products determine customer behavior
In Repeat Customer Insights the Customer First Product analysis will measure customer behavior based on the products each customer first ordered.