Final answer:
To qualify for the Refer-A-Friend bonus, referred customers must keep their account in good standing for 90 days.
Step-by-step explanation:
Referred customers must keep their account in good standing for 90 days in order to qualify for the Refer-A-Friend bonus. This means that the referred customer needs to maintain an active account and make regular payments for a period of 90 days. If they do so, they will be eligible for the bonus.