A customer is a person or organization that has purchased from your store.
It is important to separate them from people who have not purchased yet. While you might treat them the same, they are merely prospective customers and cannot be measured as customers yet.
The vast majority of ecommerce customers are one-time customers who have only one order, while the rest are returning customers or repeat customers.
Eric Davis
Is your customer acquisition spending too much?
If you're spending more to acquire a customer than they are worth, you're at risk of going out of business. Check how much you can expect your Average Customer.