What are Coinbase one referral earnings?

Could you elaborate on the concept of Coinbase One referral earnings? I'm curious to understand how the referral program works and what kind of incentives are offered to those who successfully refer new users to Coinbase One. Specifically, I'm wondering if these earnings are in the form of cryptocurrency, fiat currency, or other rewards. Additionally, I'd like to know if there are any limitations or requirements for earning referral earnings and if there's a cap on the amount that can be earned. Clarifying these details would help me determine if the referral program is worth exploring.