Why doesn't this coupon code look familiar? (single-use codes)

If a customer ever asks you about a coupon code they received from you, and you do not recognize the code, it is quite possible that they have received a single-use code. This is simply a system-generated child coupon code that can be used once and disposed of. Some of our features use these single-use codes to make sure that the coupon cannot be abused in any way but also to make sure that a customer who qualifies for that particular deal more than once can receive it more than once. 

For example, if you are using automatic email rules, you may have a coupon called BOGOAPP that provides the user with a buy one, get one free deal on an appetizer for their next purchase. Maybe you have this set to mail out whenever a customer reaches a total of $200 spent through online ordering. 

When the customer receives their email, it may give them a random coupon code ryh7643h that is technically the BOGOAPP coupon with their own special, unique code.

What is the benefit of using this instead of just setting the max usage to 1 per customer?

Let's say that your customer is told they can use BOGOAPP as a coupon code. They can tell all their friends and each friend could use that coupon code without having met the criteria. However, with a single-use code, it can only be used 1 time total, and you do not have to keep recreating the same coupon.

Also, if a customer qualifies for that coupon more than once (like maybe once they spend $200 and again when they spend $500), they will receive a different unique code which will allow them to use it again as specified.